There comes a point in every plot where the victim starts to suspect; and looks back, and sees a trail of events all pointing in a single direction. And when that point comes, Father had explained, the prospect of the loss may seem so unbearable, and admitting themselves tricked may seem so humiliating, that the victim will yet deny the plot, and the game may continue long after.

Father had warned Draco not to do that again.

First, though, he'd let Mr. Avery finish eating all of the cookies he'd swindled from Draco, while Draco watched and cried. The whole lovely jar of cookies that Father had given him just a few hours earlier, for Draco had lost all of them to Mr. Avery, down to the very last one.

So it was a familiar feeling that Draco had felt in the pit of his stomach, when Gregory told him about The Kiss.

Sometimes you looked back, and saw things...

(In a lightless classroom - you couldn't quite call it unused any more, since it'd seen weekly use over the last few months - a boy sat enshrouded in a hooded cowl, with an unlighted crystal globe on the desk in front of him. Thinking in silence, thinking in darkness, waiting for an opening door to let in the light.)

Harry had shoved Granger away and said, I told you, no kissing!

Harry would probably say something like, She just did it to annoy me, last time, just like she made me go on that date.

But the verified story was that Granger had been willing to face the Dementor again in order to help Harry; that she had kissed Harry, crying, when he was lost in the depths of Dementation; and that her kiss had brought him back.

That didn't sound like rivalry, even friendly rivalry.

That sounded like the kind of friendship you usually didn't see even in plays.

Then why had Harry made his friend climb the icy walls of Hogwarts?

Because that was the sort of thing Harry Potter did to his friends?

Father had told Draco that to fathom a strange plot, one technique was to look at what ended up happening, assume it was the intended result, and ask who benefited.

What had ended up happening as the result of Draco and Granger fighting Harry Potter together... was that Draco had started to feel a lot friendlier toward Granger.

Who benefited from the scion of Malfoy becoming friends with a mudblood witch?

Who benefited, that was famous for exactly that sort of plot?

Who benefited, that could possibly be pulling Harry Potter's strings?

Dumbledore.

And if that was true then Draco would have to go to Father and tell him everything, no matter what happened after that, Draco couldn't imagine what would happen after that, it was awful beyond imagining. Which made him want to cling desperately to the last shred of hope that it wasn't all what it looked like...

...Draco remembered that, too, from Mr. Avery's lesson.

Draco hadn't planned to confront Harry yet. He was still trying to think of an experimental test, something that Harry wouldn't just see through and fake. But then Vincent had come with the message that Harry wanted to meet early this week, on Friday instead of Saturday.

And so here Draco was, in a dark classroom, an unlit crystal globe on his desk, waiting.

Minutes passed.

Footsteps approached.

The door made a gentle creak as it swung open into the classroom, revealing Harry Potter dressed in his own hood and cowl; Harry stepped forward into the dark classroom, and the sturdy door closed behind him with a faint click.

Draco tapped the crystal globe, and the classroom lit with bright green light. Green light projected shadows of the desks onto the floor, and glared back at him from the curved chair-backs, photons bouncing off the wood in such fashion that the angle of incidence equaled the angle of reflection.

At least that much of what he'd learned wasn't likely to be a lie.

Harry had flinched as the light went on, halting for a moment, then resumed his approach. "Hello, Draco," Harry said quietly, drawing back his hood as he came to Draco's desk. "Thank you for coming, I know it's not our usual time -"

"You're welcome," Draco said flatly.

Harry dragged one of the chairs to face Draco across his desk, the legs making a slight screeching sound on the floor. He spun the chair so that it was facing the wrong way, and sat down straddling it, his arms folded across the back of the chair. The boy's face was pensive, frowning, serious, looking very adult even for Harry Potter.

"I have an important question to ask you," said Harry, "but there's something else I want us to do before that."

Draco said nothing, feeling a certain weariness. Part of him just wanted it all to be over with already.

"Tell me, Draco," said Harry. "Why don't Muggles ever leave ghosts behind when they die?"

"Because Muggles don't have souls, obviously," Draco said. He didn't even realize until after he'd said it that it might contradict Harry's politics, and then he didn't care. Besides, it was obvious.

Harry's face showed no surprise. "Before I ask my important question, I want to see if you can learn the Patronus Charm."

For a moment the sheer nonsequitur stumped Draco. Good old impossible-to-predict-or-understand Harry Potter. There were times when Draco wondered whether Harry was deliberately this disorienting as a tactic.

Then Draco understood, and shoved himself up and away from his desk in a single angry motion. That was it. It was over. "Like Dumbledore's servants," he spat.

"Like Salazar Slytherin," Harry said steadily.

Draco almost stumbled over his own feet in the middle of his first stride toward the door.

Slowly, Draco turned back toward Harry.

"I don't know where you came up with that," said Draco, "but it's wrong, everyone knows the Patronus Charm is a Gryffindor spell -"

"Salazar Slytherin could cast a corporeal Patronus Charm," Harry said. Harry's hand darted into his robes, brought out a book whose title was written as white on green, and so almost impossible to read in the green light; but it looked old. "I discovered that when I was researching the Patronus Charm before. And I found the original reference and checked the book out of the library just in case you didn't believe me. The author of this book doesn't think there's anything unusual about Salazar being able to cast a Patronus, either; the belief that Slytherins can't do that must be recent. And as a further historical note, though I don't have the book with me, Godric Gryffindor never could."

After the first six times Draco had tried calling Harry's bluff, on six successively more ridiculous occasions, he'd realized that Harry just didn't lie about what was written in books. Still, when Harry's hands opened the book and laid it out to the place of a bookmark, Draco leaned over and studied the place where Harry's finger pointed.

Then the fires of Ravenclaw fell upon the darkness that had cloaked the left wing of Lord Foul's army, breaking it, and it was revealed that the Lord Gryffindor had spoken true; the fear they all had felt was not natural in its source, but coming from thrice a dozen Dementors, who had been promised the souls of the defeated. At once the Lady Hufflepuff and Lord Slytherin brought forth their Patronuses, a vast angry badger and a bright silver serpent, and the defenders lifted their heads as the shadow passed from their hearts. And Lady Ravenclaw laughed, remarking that Lord Foul was a great fool, for now his own army would be subject to the fear, but not the defenders of Hogwarts. Yet the Lord Slytherin said, "No fool he, that much I know." And the Lord Gryffindor beside him studied the battlefield with a frown upon his face...

Draco looked back up. "So?"

Harry closed the book and put it into his pouch. "Chaos and Sunshine both have soldiers that can cast corporeal Patronus Charms. Corporeal Patronuses can be used to convey messages. If you can't learn the spell, Dragon Army will be at a severe military disadvantage -"

Draco didn't care about that right now, and told Harry so. His voice was sharper than it probably should have been.

Harry didn't blink. "Then I'm calling in the favor you owe me from that time I stopped a riot from breaking out, on our first day of broomstick lessons. I'm going to try to teach you the Patronus Charm, and for my favor, I want you to do your honest best to learn and cast it. I trust to the honor of House Malfoy that you will."

Draco felt that certain weariness again. If Harry had asked at any other time, it would have been a fair return on favor owed, given that it wasn't actually a Gryffindor spell. But...

"Why?" Draco said.

"To find out whether you can do this thing that Salazar Slytherin could do," Harry said evenly. "This is an experimental test, and I will not tell you what it means until after you have done it. Will you?"

...It probably was a good idea to discharge that favor on something innocuous, all the more so if it was time to break with Harry Potter. "All right."

Harry drew a wand from his robes, and laid it against the globe. "Not really the best color for learning the Patronus Charm," Harry said. "Green light the exact shade of the Killing Curse, I mean. But silver is a Slytherin color too, isn't it? Dulak." The light went out, and Harry whispered the first two phrases of the Continual Light enchantment, recasting that part of it, though neither of them could have cast the whole thing by themselves. Then Harry tapped the globe again, and the room lit with a silver radiance, brilliant but still soft and gentle. Color returned to the desks and chairs, and to Harry's slightly sweaty face beneath his shock of black hair.

It took that long for Draco to realize the implication. "You saw a Killing Curse cast since the last time we met? When - how -"

"Cast the Patronus Charm," Harry said, looking more serious than ever, "and I'll tell you."

Draco pressed his hands to his eyes, shutting out the silver light. "You know, I really should remember that you're too weird for any normal plots!"

Within his self-imposed darkness, he heard the sound of Harry snickering.

Harry watched closely as Draco finished his latest run-through of the preliminary gestures, the part of the spell that was difficult to learn; the final brandish and the pronunciation didn't have to be precise. All three of the last runs had been perfect as far as Harry could see. Harry had also felt an odd impulse to adjust things that Mr. Lupin hadn't said anything about, like the angle of Draco's elbow or the direction his foot was pointing; it could have been entirely his own imagination, and probably was, but Harry had decided to go with it just in case.

"All right," Harry said quietly. There was a tension in his chest that made it a little hard to speak. "Now we don't have a Dementor here, but that's all right. We won't need one. Draco, when your father spoke to me at the train station, he said that you were the one thing in the world that was most precious to him, and he threatened to throw away all his other plans to take vengeance on me, if ever you came to harm."

"He... what?" There was a catch in Draco's voice, and a strange look on his face. "Why are you telling me that?"

"Why wouldn't I?" Harry didn't let his expression change, though he could guess what Draco was thinking; that Harry had been plotting to separate Draco from his father, and shouldn't be saying anything that would bring them closer together. "There's always been just one person who matters most to you, and I know exactly what warm and happy thought will let you cast the Patronus Charm. You told it to me at the train station before the first day of school. Once you fell off a broomstick and broke your ribs. It hurt more than anything you'd ever felt, and you thought you were going to die. Pretend that fear is coming from a Dementor, standing in front of you, wearing a tattered black cloak, looking like a dead thing left in water. And then cast the Patronus Charm, and when you brandish the wand to drive the Dementor away, think of how your father held your hand, so that you wouldn't be afraid; and then think of how much he loves you, and how much you love him, and put it all into your voice when you say Expecto Patronum. For the honor of House Malfoy, and not just because you promised me a favor. Show me you didn't lie to me that day in the train station when you told me Lucius was a good father. Show me you can do what Salazar Slytherin could do."

And Harry stepped backward, behind Draco, out of Draco's field of vision, so that Draco only faced the dusty old teacher's desk and blackboard at the front of the unused classroom.

Draco cast one look behind him, that strange look still on his face, and then turned away to face forward. Harry saw the exhalation, the inhalation. The wand twitched once, twice, thrice, and four times. Draco's fingers slid along the wand, exactly the right distances -

Draco lowered his wand.

"This is too -" Draco said, "I can't think this right, while you're watching -"

Harry turned around and started walking toward the door. "I'll come back in a minute," Harry said. "Just hold to your happy thought, and the Patronus will stay."

From behind Draco came the sound of the door opening again.

Draco heard Harry's footsteps entering the classroom, but Draco didn't turn to look.

Harry didn't say anything either. The silence stretched.

Finally -

"What does this mean?" Draco said. His voice wavered a bit.

"It means you love your father," Harry's voice said. Which was just what Draco had been thinking, and trying not to cry in front of Harry. It was too right, just too right -

Before Draco, on the floor, was the shining form of a snake that Draco recognized; a Blue Krait, a snake first brought to their manor by Lord Abraxas Malfoy after a visit to some faraway land, and Father had kept a Blue Krait in the ophidiarium ever since. The thing about the Blue Krait was that the bite wouldn't hurt much. Father had said that, and told Draco that he was never allowed to pet the snake, no matter who was watching. The venom killed your nerves so fast that you didn't have time to feel pain as the poison spread. You could die of it even after using Healing Charms. It ate other snakes. It was as Slytherin as any creature could possibly be.

That was why a Blue Krait head had been forged into the handle of Father's cane.

The bright snake darted out its tongue, which was also silver; and seemed to smile somehow, in a warmer way than any reptile should.

And then Draco realized -

"But," Draco said, still staring at the beautifully radiant snake, "you can't cast the Patronus Charm." Now that Draco had cast it himself, he understood why that was important. You could be evil, like Dumbledore, and still cast the Patronus Charm, so long as you had something bright left inside you. But if Harry Potter didn't have a single thought inside him that shone like that -

"The Patronus Charm is more complicated than you think, Draco," Harry said seriously. "Not everyone who fails at casting it is a bad person, or even unhappy. But anyway, I can cast it. I did it on my second try, after I realized what I'd done wrong facing the Dementor my first time. But, well, my life gets a little peculiar sometimes, and my Patronus came out strange, and I'm keeping it a secret for now -"

"Am I supposed to just believe that?"

"You can ask Professor Quirrell if you don't believe me," said Harry. "Ask him whether Harry Potter can cast a corporeal Patronus, and tell him that I told you to ask. He'd know the request was from me, no one else would know."

Oh, and now Draco was to trust Professor Quirrell? Still, knowing Harry, it might be true; and Professor Quirrell wouldn't lie for trivial reasons.

The glowing snake turned its head back and forth, as though seeking a prey that wasn't there, and then coiled itself into a circle, as though to rest.

"I wonder," Harry said softly, "when it was, which year, which generation, that Slytherins stopped trying to learn the Patronus Charm. When it was that people started to think, that Slytherins themselves started to think, that being cunning and ambitious was the same as being cold and unhappy. And if Salazar knew that his students didn't even bother showing up to learn the Patronus Charm any more, I wonder, would he wish that he'd never been born? I wonder how it all went wrong, when Slytherin's House went wrong."

The shining creature winked out, the turmoil rising in Draco making it impossible to sustain the Charm. Draco spun on Harry, he had to control himself not to raise his wand. "What do you know about Slytherin House or Salazar Slytherin? You were never Sorted into my House, what gives you the right to -"

And that was when Draco finally realized.

"You did get Sorted into Slytherin!" Draco said. "You did, and afterwards you, you somehow, you snapped your fingers -" Draco had once asked Father if it would be cleverer to get Sorted into some other House so that everyone would trust him, and Father had smiled and said that he'd thought of that too at Draco's age, but there was no way to fool the Sorting Hat...

...not until Harry Potter came along.

How had he ever bought for one minute that Harry was a Ravenclaw?

"An interesting hypothesis," Harry said equably. "Do you know, you're the second person in Hogwarts to come up with a theory along those lines? At least you're the second that's actually said so to my face -"

"Snape," Draco said with certainty. His Head of House was no fool.

"Professor Quirrell, of course," said Harry. "Though come to think, Severus did ask me how I managed to stay out of his House, and whether I had something the Sorting Hat wanted. I suppose you could say you're number three. Oh, but Professor Quirrell's theory was a little different than yours, though. May I have your word not to repeat it?"

Draco nodded without even really thinking about it. What was he supposed to do, say no?

"Professor Quirrell thought that Dumbledore wasn't happy with the Hat's choice for the Boy-Who-Lived."

And the instant Harry said it, Draco knew, he knew that it was true, it was just obvious. Who did Dumbledore even think he was fooling?

...well, besides every single other person in Hogwarts except Snape and Quirrell, Harry might even believe it himself...

Draco stumbled back over to his desk in something of a daze, and sat down hard enough to hurt slightly. This sort of thing happened around once a month with Harry, and it hadn't happened yet in January, so it was time.

His fellow Slytherin, who might or might not think himself a Ravenclaw, sat back down in the chair he'd used earlier, now sitting on it crosswise, and looking up intently at Draco.

Draco didn't know what he should be doing now, whether he should be trying to persuade the lost Slytherin boy that, no, he wasn't actually a Ravenclaw... or trying to figure out whether Harry was in league with Dumbledore, though that suddenly seemed less likely... but then why had Harry set up the whole thing with him and Granger...

He really should have remembered that Harry was too weird for any normal plots.

"Harry," Draco said. "Did you deliberately antagonize me and General Sunshine just so we'd work together against you?"

Harry nodded without hesitation, as though it was the most normal thing in the world, and nothing to be ashamed of.

"The whole thing with the gloves and making us climb up the walls of Hogwarts, the only point was to make me and Granger more friendly toward each other. And even before then. You've been plotting it for a really long time. Since the beginning."

Again the nod.

"WHYYYYY?"

Harry's eyebrows lifted for a moment, the only reaction he showed to Draco shrieking so loudly in the closed classroom that it hurt his own ears. WHY, WHY, WHY did Harry Potter DO this sort of thing...

Then Harry said, "So that Slytherins will be able to cast the Patronus Charm again."

"That... doesn't... make... SENSE!" Draco was aware that he was losing control of his voice, but he didn't seem able to stop himself. "What does that have to do with Granger?"

"Patterns," Harry said. His face was very serious now, and very grave. "Like a quarter of children born to Squib couples being wizards. A simple, unmistakable pattern you would recognize instantly, if you knew what you were looking at; even though, if you didn't know, you wouldn't even realize it was a clue. The poison in Slytherin House is something that's been seen before in the Muggle world. This is an advance prediction, Draco, I could have written it down for you before our first day of school, just from hearing you talk in King's Cross Station. Let me describe some really pathetic sorts of people that hang around at your father's political rallies, pureblood families that would never be invited to dinner at Malfoy Manor. Bearing in mind that I've never met them, I'm just predicting it from recognizing the pattern of what's happening to Slytherin House -"

And Harry Potter proceeded to describe the Parkinsons and Montagues and Boles with a calmly cutting accuracy that Draco wouldn't have dared think to himself in case there was a Legilimens around, it was beyond insult, they would kill Harry if they ever heard...

"To sum up," Harry finished, "they don't have any power themselves. They don't have any wealth themselves. If they didn't have Muggleborns to hate, if all the Muggleborns vanished the way they say they want, they'd wake up one morning and find they had nothing. But so long as they can say purebloods are superior, they can feel superior themselves, they can feel like part of the master class. Even though your father would never dream of inviting them to dinner, even though there's not one Galleon in their vaults, even if they did worse on their OWLs than the worst Muggleborn in Hogwarts. Even if they can't cast the Patronus Charm any more. Everything is the Muggleborns' fault to them, they have someone besides themselves to blame for their own failures, and that makes them even weaker. That's what Slytherin House is becoming, pathetic, and the root of the problem is hating Muggleborns."

"Salazar Slytherin himself said that mudbloods needed to be cast out! That they were weakening our blood -" Draco's voice had risen to a shout.

"Salazar was wrong as a question of simple fact! You know that, Draco! And that hatred is poisoning your whole House, you couldn't cast the Patronus Charm using a thought like that!"

"Then why could Salazar Slytherin cast the Patronus Charm?"

Harry was wiping sweat from his forehead. "Because things have changed between then and now! Listen, Draco, three hundred years ago you could find great scientists, as great as Salazar in their own way, who would have told you that some other Muggles were inferior because of their skin color -"

"Skin color?" said Draco.

"I know, skin color instead of anything important like blood purity, isn't it ridiculous? But then something in the world changed, and now you can't find any great scientists who still think skin color should matter, only loser people like the ones I described to you. Salazar Slytherin made the mistake when everyone else was making it, because he grew up believing it, not because he was desperate for someone to hate. There were a few people who did better than everyone else around them, and they were exceptionally good. But the ones who just accepted what everyone else thought weren't exceptionally evil. The sad fact is that most people just don't notice a moral issue at all unless someone else is pointing it out to them; and once they're as old as Salazar was when he met Godric, they've lost the ability to change their minds. Only then Hogwarts was built, and Hogwarts started sending acceptance letters to Muggleborns like Godric insisted, and more and more people began to notice that Muggleborns weren't any different. Now it's a big political issue instead of something that everyone just believes without thinking about it. And the correct answer is that Muggleborns aren't any weaker than purebloods. So now the people who end up siding with what Salazar once believed, are either people who grew up in very closed pureblood environments like you, or people who are so pathetic themselves that they're desperate for someone to feel superior to, people who love to hate."

"That doesn't... that doesn't sound right..." Draco's voice said. His ears listened, and wondered that he couldn't come up with anything better to say.

"It doesn't? Draco, you know now there's nothing wrong with Hermione Granger. You had trouble dropping her off a roof, I hear. Even though you knew she'd taken a Feather-Falling Potion, even though you knew she was safe. What sort of person do you think wants to kill her, not for any wrong she did to them, just because she's a Muggleborn? Even though she's, she's just a young girl who would help them with their homework in a second, if they ever asked her," Harry's voice broke, "what sort of person wants her to die?"

Father -

Draco felt split in two, he seemed to be having a problem with dual vision, Granger is a mudblood, she should die and a girl hanging from his hand on the rooftop, like seeing double, seeing double -

"And anyone who doesn't want Hermione Granger to die, won't want to hang around the sort of people who do! That's all people think Slytherin is now, not clever planning, not trying to achieve greatness, just hating Muggleborns! I paid Morag a Sickle to ask Padma why she hadn't gone to Slytherin, we both know she got the option. And Morag told me that Padma just gave her a look and said that she wasn't Pansy Parkinson. You see? The best students with the virtues of more than one House, the students with choices, they go under the Hat thinking anywhere but Slytherin, and someone like Padma ends up in Ravenclaw. And... I think the Sorting Hat tries to maintain a balance in the Sorting, so it fills out the ranks of Slytherin with anyone who isn't repelled by all the hatred. So instead of Padma Patil, Slytherin gets Pansy Parkinson. She's not very cunning, and she's not very ambitious, but she's the sort of person who doesn't mind what Slytherin is turning into. And the more Padmas go to Ravenclaw and the more Pansies go to Slytherin, the more the process accelerates. It's destroying Slytherin House, Draco!"

It had a ring of awful truth, Padma had belonged in Slytherin... and instead Slytherin got Pansy... Father rallied lesser families like the Parkinsons because they were convenient sources of support, but Father hadn't realized the consequences of associating Slytherin's name with them...

"I can't -" Draco said, but he wasn't even sure what he couldn't do - "What do you want from me?"

"I'm not sure how to heal Slytherin House," Harry said slowly. "But I know it's something you and I will end up having to do. It took centuries for science to dawn over the Muggle world, it only happened slowly, but the stronger science got, the further that sort of hatred retreated." Harry's voice was quiet, now. "I don't know exactly why it worked that way, but that's how it happened historically. As though there's something in science like the shine of the Patronus Charm, driving back all sorts of darkness and madness, not right away, but it seems to follow wherever science goes. The Enlightenment, that was what it was called in the Muggle world. It has something to do with seeking the truth, I think... with being able to change your mind from what you grew up believing... with thinking logically, realizing that there's no reason to hate someone because their skin is a different color, just like there's no reason to hate Hermione Granger... or maybe there's something to it that even I don't understand. But the Enlightenment is something that you and I belong to now, both of us. Fixing Slytherin House is just one of the things we have to do."

"Let me think," Draco said, his voice coming out in something of a croak, "please," and he rested his head in his hands, and thought.

Draco thought for a while, with his palms over his eyes to shut out the world, no sound but his and Harry's breathing. All the persuasive reasonableness of what Harry said, the evident grains of truth that it contained; and against that, the obvious, the perfectly and entirely obvious hypothesis about what was really going on...

After a time, Draco finally raised his head.

"It sounds right," Draco said quietly.

A huge smile broke out on Harry's face.

"So," Draco continued, "is this where you bring me to Dumbledore, to make it official?"

He kept his voice very casual as he said it.

"Oh, yeah," Harry said. "That was the thing I was going to ask you about, actually -"

Draco's blood froze in his veins, froze solid and shattered -

"Professor Quirrell said something to me that got me thinking, and, well, no matter how you answer this question, I'm already stupid for having not asked you a lot earlier. Everyone in Gryffindor thinks Dumbledore is a saint, the Hufflepuffs think he's crazy, the Ravenclaws are all proud of themselves for having worked out that he's only pretending to be crazy, but I never asked anyone in Slytherin. I'm supposed to know better than to make that sort of mistake. But if even you think Dumbledore's okay to conspire with on fixing Slytherin House, I guess I didn't miss anything important."

...

...

...

"You know," Draco said, his voice remarkably calm, all things considered, "every time I wonder if you do things like this just to annoy me, I tell myself that it has to be accidental, no one could possibly do this sort of thing on purpose even if they tried until blood trickled out of their ears. That's the only reason I'm not going to strangle you now."

"Huh?"

And then strangle himself, because Harry had grown up with Muggles, and then Dumbledore had smoothly diverted him from Slytherin to Ravenclaw, so it was perfectly plausible that Harry might not know anything, and Draco had never thought to tell him.

Or else Harry had guessed that Draco wouldn't join up with Dumbledore so readily, and this itself was just the next step of Dumbledore's plan...

But if Harry really didn't know about Dumbledore, then warning him had to take precedence over everything.

"All right," Draco said, after he'd had a chance to organize his thoughts. "I don't know where to start, so I'll just start somewhere." Draco drew a deep breath. This was going to take a while. "Dumbledore murdered his little sister, and got away with it because his brother wouldn't testify against him -"

Harry listened with increasing worry and dismay. Harry had been prepared, he'd thought, to take the blood purist side of the story with a grain of salt. The trouble was that even after you added an enormous amount of salt, it still didn't sound good.

Dumbledore's father had been convicted of using Unforgivable Curses on children, and died in Azkaban. That was no sin of Dumbledore's, but it would be a matter of public record. Harry could check that part, and see whether all of this had been made up out of thin air by the blood purists.

Dumbledore's mother had died mysteriously, shortly before his younger sister died in what the Aurors had ruled to be murder. Supposedly that sister had been brutalized by Muggles and never spoken again after that; which, Draco pointed out, sounded remarkably like a botched Obliviation.

After Harry's first few interruptions, Draco had seemed to pick up on the general principle, and was now presenting the observations first and the inferences afterward.

"- so you don't have to take my word for it," said Draco, "you can see it, right? Anyone in Slytherin can. Dumbledore waited to fight his duel with Grindelwald until the exact moment when it would look best for Dumbledore, after Grindelwald had ruined most of Europe and built up a reputation as the most terrible Dark Wizard in history, and just when Grindelwald had lost the gold and blood sacrifices he was getting from his Muggle pawns and was about to start heading downhill. If Dumbledore was really the noble wizard he pretended to be, he'd have fought Grindelwald long before that. Dumbledore probably wanted Europe ruined, it was probably part of their plan together, he only attacked Grindelwald after his puppet failed him. And that big flashy duel wasn't real, there's no way two wizards would be so exactly matched that they'd fight for twenty whole hours until one of them fell over from exhaustion, that was just Dumbledore making it look more spectacular." Here Draco's voice became more indignant. "And that got Dumbledore made Chief Warlock of the Wizengamot! The Line of Merlin Unbroken, corrupted after fifteen hundred years! And then he became Supreme Mugwump on top of that, and he already had Hogwarts to use as an invincible fortress - Headmaster and Chief Warlock and Supreme Mugwump, no normal person would try to do all that at once, how can anyone not see that Dumbledore's trying to take over the world?"

"Pause," Harry said, and closed his eyes to think.

It wasn't any worse than what you would have heard about the West in Stalin's Russia, and none of that would have been true. Though the blood purists wouldn't be able to get away with making stuff up entirely... or would they? The Daily Prophet had shown a pronounced tendency to make stuff up... but then again, when they stuck out their neck too far on the Weasley betrothal, they had been called on it and they had been embarrassed...

Harry opened his eyes, and saw that Draco was watching him with a steady, waiting gaze.

"So when you asked me if it was time to join up with Dumbledore, that was just a test."

Draco nodded.

"And before that, when you said it sounded right -"

"It sounds right," said Draco. "But I don't know if I can trust you. Are you going to complain about my testing you, Mr. Potter? Are you going to say that I fooled you? That I led you on?"

Harry knew he should smile like a good sport, but he couldn't really, it was too much of a disappointment.

"You're right, it's fair, I can't complain," Harry said instead. "So what about He-Who-Must-Not-Be-Named? Not as bad as he was made out to be?"

Draco looked bitter, at that. "So you think it's all just making Father's side look good and Dumbledore's side look bad, and that I believe it all myself just because Father told me."

"It's a possibility I'm considering," Harry said evenly.

Draco's voice was low and intense. "They knew. My father knew, his friends knew. They knew the Dark Lord was evil. But he was the only chance anyone had against Dumbledore! The only wizard anywhere who was powerful enough to fight him! Some of the other Death Eaters were truly evil too, like Bellatrix Black - Father isn't like that - but Father and his friends had to do it, Harry, they had to, Dumbledore was taking over everything, the Dark Lord was the only hope anyone had left!"

Draco was staring hard at Harry. Harry met the gaze, trying to think. Nobody ever thought of themselves as the villain of their own story - maybe Lord Voldemort did, maybe Bellatrix did, but Draco certainly didn't. That the Death Eaters were bad guys was not in question. The question was whether they were the bad guys; whether there was one villain in the story, or two...

"You're not convinced," Draco said. He looked worried, and a little angry. Which didn't surprise Harry. He was pretty sure Draco himself believed all this.

"Should I be convinced?" Harry said. He didn't look away. "Just because you believe it? Are you a strong enough rationalist now that your belief is strong evidence to me, because you'd be very unlikely to believe it if it weren't true? When I met you, you weren't that strong. Everything you told me, did you rethink it after you awakened as a scientist, or is it just something you grew up believing? Can you look me in the eyes and swear to me upon the honor of House Malfoy that if there's one untruth buried in what you said, one thing that got added on just to make Dumbledore look a little worse, you would have noticed?"

Draco started to open his mouth, and Harry said, "Don't. Don't stain the honor of House Malfoy. You're not that strong yet, and you should know it. Listen, Draco, I've started to notice some worrying things myself. But there's nothing definite, nothing certain, it's all just deductions and hypotheses and untrustworthy witnesses... And there's nothing certain in your story, either. Dumbledore might've had some other good reason not to fight Grindelwald years earlier - though it would have to be a pretty good excuse, especially considering what was happening on the Muggle side of things... but still. Is there one clearly evil thing that Dumbledore's done for certain, so I don't have to wonder?"

Draco's breathing was harsh. "All right," Draco said in an uneven voice, "I'll tell you what Dumbledore did." From Draco's robes came a wand, and Draco said "Quietus", then "Quietus" again, but he got the pronunciation wrong a second time, and finally Harry took out his own wand and did it.

"There," said Draco hoarsely, "once upon a time there, there was a girl, and her name was Narcissa, and she was the prettiest, the smartest, the most cunning girl that was ever Sorted into Slytherin, and my father loved her, and they married, and she wasn't a Death Eater, she wasn't a fighter, all she ever did was love Father -" Draco stopped there, because he was crying.

Harry felt sick to his stomach. Draco had never talked about his mother, not once, he should have noticed that earlier. "She... got in the way of a curse?"

Draco's voice came out in a scream. "Dumbledore burned her to death in her own bedroom!"

In a classroom filled with soft silver light, one boy is staring at another boy, who is sobbing, wiping frantically at his eyes with the sleeves of his robes.

It was hard for Harry to stay balanced, to keep withholding judgment, it was too emotional, there was something that either wanted to start tears from his own eyes in sympathy with Draco, or know that it wasn't true...

Dumbledore burned her to death in her own bedroom!

That...

...didn't sound like Dumbledore's style...

...but you could only think that thought so many times, before you started to wonder about the trustworthiness of that whole 'style' concept.

"It, it must have hurt horribly," Draco said, his voice shaking, "Father never talks about it at all, you don't ever talk about it in front of him, but Mr. Macnair told me, there were scorch marks all over the bedroom, from how Mother must have struggled while Dumbledore burned her alive. That is the debt Dumbledore owes to House Malfoy and we will have his life for it!"

"Draco," Harry said, he let all of the hoarseness into his own voice, it would be wrong to sound calm, "I'm sorry, I'm so sorry for asking, but I have to know, how do you know it was Dumble-"

"Dumbledore said he did it, he told Father it was a warning! And Father couldn't testify under Veritaserum because he was an Occlumens, he couldn't even get Dumbledore put on trial, Father's own allies didn't believe him after Dumbledore just denied everything in public, but we know, the Death Eaters know, Father wouldn't have any reason to lie about that, Father would want us to take revenge on the right person, can't you see that Harry?" Draco's voice was wild.

Unless Lucius did it himself, of course, and found it more convenient to blame Dumbledore.

Although... it also didn't seem like Lucius's style. And if he had murdered Narcissa, it would have been smarter to pin the blame on an easier victim instead of losing political capital and credibility by going after Dumbledore...

In time, Draco stopped crying, and looked at Harry. "Well?" said Draco, sounding like he wanted to spit the words. "Is that evil enough for you, Mr. Potter?"

Harry looked down at where his arms rested on the back of his chair. He couldn't meet Draco's eyes any more, the pain in them was too raw. "I wasn't expecting to hear that," Harry said softly. "I don't know what to think any more."

"You don't know?" Draco's voice rose to a shriek, and he stood up abruptly from his desk -

"I remembered the Dark Lord killing my parents," Harry said. "When I went in front of the Dementor the first time, that was what I remembered, the worst memory. Even though it was so long ago. I heard them dying. My mother begged the Dark Lord not to kill me, not Harry, please no, take me, kill me instead! That's what she said. And the Dark Lord mocked her, and laughed. Then, I remember, the flash of green light -"

Harry looked up at Draco.

"So we could fight," Harry said, "we could just keep on with the same fight. You could tell me that it was right for my mother to die, because she was the wife of James, who killed a Death Eater. But bad for your mother to die, because she was innocent. And I could tell you that it was right for your mother to die, that Dumbledore must have had some reason that made it okay to burn her alive in her own bedroom; but bad for my mother to die. But you know, Draco, either way, wouldn't it be obvious that we were just being biased? Because the rule that says that it's wrong to kill innocent people, that rule can't switch on for my mother and off for yours, and it can't switch on for your mother and off for mine. If you tell me that Lily was an enemy of the Death Eaters and it's right to kill your enemies, then the same rule says that Dumbledore was right to kill Narcissa, since she was his enemy." Harry's voice went hoarse. "So if the two of us are going to agree on anything, it's going to be that neither of their deaths were right and that no one's mother should die any more."

The fury boiling inside Draco was so great that he could barely stop himself from storming out of the room; all that halted him was the recognition of a critical moment; and a small remnant of friendship, a tiny flash of sympathy, for he had forgotten, he'd forgotten, that Harry's mother and father were dead by the Dark Lord's hand.

The silence stretched.

"You can talk," Harry said, "Draco, talk to me, I won't get angry - are you thinking, I don't know, that Narcissa dying was much worse than Lily dying? That it's wrong for me even to make the comparison?"

"I guess I was stupid too," Draco said. "All this time, all this time I forgot that you must hate the Death Eaters for killing your parents, hate Death Eaters the way I hate Dumbledore." And Harry had never said anything, never reacted when Draco talked about Death Eaters, kept it hidden - Draco was a fool.

"No," Harry said. "It's not - it's not like that, Draco, I, I don't even know how to explain to you, except to say that a thought like that, wouldn't," Harry's voice choked, "you wouldn't ever be able to use it, to cast the Patronus Charm..."

Draco felt a sudden wrench in his heart, unwanted but he felt it. "Are you pretending you're just going to forget about your own parents? Are you saying I should just forget about Mother?"

"So you and I have to be enemies then?" Now Harry's voice was growing equally wild. "What have we ever done to each other that means we have to be enemies? I refuse to be trapped like that! Justice can't mean that both of us should attack each other, it doesn't make sense!" Harry stopped, took a deep breath, ran his fingers back through the deliberate mess of his hair - the fingers came away sweaty, Draco could see it. "Draco, listen, we can't expect to meet on everything right away, you and I. So I won't ask you to say that the Dark Lord was wrong to kill my mother, just say that it was... sad. We won't talk about whether or not it was necessary, whether it was justified. I'll just ask you to say that it was sad that it happened, that my mother's life was valuable too, you'll just say that for now. And I'll say it was sad that Narcissa died, because her life was also worth something. We can't expect to agree on everything right away, but if we start out by saying that every life is precious, that it's sad when anyone dies, then I know we'll meet someday. That's what I want you to say. Not who was right. Not who was wrong. Just that it was sad when your mother died, and sad when my mother died, and it would be sad if Hermione Granger died, every life is precious, can we agree on that and let the rest go by for now, is it enough if we just agree on that? Can we, Draco? That seems... more like a thought someone could use to cast the Patronus Charm."

There were tears in Harry's eyes.

And Draco was getting angry again. "Dumbledore killed Mother, it's not enough to just say it's sad! I don't understand what you think you have to do, but the Malfoys have to take revenge!" Not avenging the deaths of family went beyond weakness, beyond dishonor, you might as well not exist.

"I'm not arguing with that," Harry said quietly. "But will you say that Lily Potter's death was sad? Just say that one thing?"

"That's..." Draco was having difficulty finding words again. "I know, I know how you feel, but don't you see Harry, even if I just say that Lily Potter's death was sad, that's already going against the Death Eaters!"

"Draco, you've got to be able to say the Death Eaters were wrong about some things! You have to, you can't progress as a scientist otherwise, there'll be a roadblock in your way, an authority you can't contradict. Not every change is an improvement, but every improvement is a change, you can't do anything better unless you can manage to do it differently, you've got to let yourself do better than other people! Even your father, Draco, even him. You've got to be able to point to something your father did and say it was mistaken, because he wasn't perfect, and if you can't say that, you can't do better."

Father had warned him, every night before he went to sleep for a month before he went to Hogwarts, that there would be people with this goal.

"You're trying to break me loose of Father."

"Trying to break a part of you loose," said Harry. "Trying to let you fix some things your father got mistaken. Trying to let you do better. But not... trying to break your Patronus!" Harry's voice got softer. "I wouldn't want to break something bright like that. Who knows, fixing Slytherin House might need that, too..."

It was getting to Draco, that was the thing, despite everything it was getting to him, you had to be really careful around Harry because his arguments sounded so convincing even when he was wrong. "And what you're not admitting is that Dumbledore told you that you could avenge your parents' deaths by taking Lord Malfoy's son from him -"

"No. No. That part's just wrong." Harry took a deep breath. "I did not know who Dumbledore was, or who the Dark Lord was, or who the Death Eaters were, or how my parents died, until three days before I came to Hogwarts. The day you and I first met in the clothes shop, that was the day I learned. And Dumbledore doesn't even like Muggle science, or he says he doesn't, I got a chance to probe him on it once. The thought of taking revenge on the Death Eaters through you has never crossed my mind, not even once until now. I didn't know who the Malfoys were when I met you in the clothes shop, and then I liked you."

There was a long silence.

"I wish I could trust you," Draco said. His voice was shaking. "If I could just know you were telling the truth, everything would be so much simpler -"

And then suddenly it came to Draco.

The way to know whether Harry Potter really meant everything he said, about wanting to fix Slytherin House, about being sad that Mother had died.

It would be illegal, and since he'd have to do it without Father's help, it would be dangerous, he couldn't even trust Harry Potter to help, but...

"All right," Draco said. "I've thought of a definitive experiment."

"What is it?"

"I want to give you a drop of Veritaserum," Draco said. "Just one drop, so you can't lie, but not enough to make you answer anything. I don't know where I'll get it, but I'll make certain it's safe -"

"Um," Harry said. There was a helpless look on his face. "Draco, um -"

"Don't say it," Draco said. His voice was firm and calm. "If you say no, that's my experimental result right there."

"Draco, I'm an Occlumens -"

"OH THAT IS SUCH A LIE -"

"I was trained by Mr. Bester. Professor Quirrell set it up. Look, Draco, I'll take one drop of Veritaserum if you can get it, I'm just warning you that I'm an Occlumens. Not a perfect Occlumens, but Mr. Bester said I was putting up a complete block, and I could probably beat Veritaserum."

"You're in your first year at Hogwarts! That's just crazy!"

"Know a Legilimens you can trust? I'll be happy to demonstrate - look, Draco, I'm sorry, but doesn't the fact that I told you count for something? I could have just let you do it, you know."

"WHY? Why are you always like this, Harry? Why do you have to mess everything up even when it's IMPOSSIBLE? And stop smiling, this isn't funny!"

"I'm sorry, I'm sorry, I know it's not funny, I -"

It took a while for Draco to get himself under control.

But Harry was right. Harry could have just let Draco administer the Veritaserum. If he really was an Occlumens... Draco didn't know who he could ask to try Legilimency, but he could at least ask Professor Quirrell if it was true... Could Draco trust Professor Quirrell? Maybe Professor Quirrell would just say anything Harry asked him to.

Then Draco remembered the other thing Harry had told him to ask Professor Quirrell, and thought of a different test.

"You know," said Draco. "You know what it costs me, if I agree that the poison in Slytherin's House is hating Muggleborns, and say that Lily Potter's death was sad. And that's part of your plan, don't tell me it's not."

Harry said nothing, which was wise of him.

"There's something I want from you in return," said Draco. "And before then, an experimental test I want to try -"

Draco pushed open the door to which the portraits had directed them, and this time it was the right door. Before them was a small empty place of stone set against the night sky. Not a roof like the one he'd dropped Harry from, but a tiny and proper courtyard, far above the ground. With proper railings, elaborate traceries of stone that flushed seamlessly into the stone floor... How so much artistry had been infused into the creation of Hogwarts was something that still awed Draco every time he thought about it. There must have been some way to do it all at once, no one could have detailed so much piece by piece, the castle changed and every new piece was like that. It was so far beyond the wizardry of these fading days that no one would have believed it if they hadn't seen the proof in Hogwarts itself.

Cloudless and cold, the winter night sky; it got dark long before students' curfew, in the final days of January.

The stars shining brightly, in the clear air.

Harry had said that being under the stars would help him.

Draco touched his chest with his wand, slid his fingers in a practiced motion, and said, "Thermos." A warmth spread through him, starting from his heart; the wind went on blowing on his face, but he was no longer cold.

"Thermos," Harry's voice said behind him.

They went together to the railing, to look down at the ground a long way below. Draco tried to figure if they were in one of the towers that could be seen from outside, and found that right now he couldn't quite seem to picture how Hogwarts looked from outside. But the ground below was always the same; he could see the Forbidden Forest as a vague outline, and moonlight glittering from the Hogwarts Lake.

"You know," Harry's voice said quietly from beside him where his arms leaned on the railing next to Draco's, "one of the things that Muggles get really wrong, is that they don't turn all their lights out at night. Not even for one hour every month, not even for fifteen minutes once a year. The photons scatter in the atmosphere and wash out all but the brightest stars, and the night sky doesn't look the same at all, not unless you go far away from any cities. Once you've looked up at the sky over Hogwarts, it's hard to imagine living in a Muggle city, where you wouldn't be able to see the stars. You certainly wouldn't want to spend your whole life in Muggle cities, once you'd seen the night sky over Hogwarts."

Draco glanced at Harry, and found that Harry was craning his neck to stare up at where the Milky Way arched across the darkness.

"Of course," Harry went on, his voice still quiet, "you can't ever see the stars properly from Earth, either, the air always gets in the way. You have to look from somewhere else, if you want to see the real thing, the stars burning hard and bright, like their true selves. Have you ever wished that you could just whisk yourself up into the night sky, Draco, and go look at what there is to see around other Suns than ours? If there were no limit to the power of your magic, is that one of the things you would do, if you could do anything?"

There was a silence, and then Draco realized that he was expected to answer. "I didn't think of it before," Draco said. Without any conscious decision, his voice came out as soft and hushed as Harry's. "Do you really think anyone would ever be able to do that?"

"I don't think it'll be that easy," said Harry. "But I know I don't mean to spend my whole life on Earth."

It would have been something to laugh at, if Draco hadn't known that some Muggles had already left, without even using magic.

"To pass your test," Harry said, "I'm going to have to say what it means to me, that thought, the whole thing, not the shorter version I tried to explain to you before. But you should be able to see it's the same idea, only more general. So my version of the thought, Draco, is that when we go out into the stars, we might find other people there. And if so, they certainly won't look like we do. There might be things out there that are grown from crystal, or big pulsating blobs... or they might be made of magic, now that I think about it. So with all that strangeness, how do you recognize a person? Not by the shape, not by how many arms or legs it has. Not by the sort of substance it's made out of, whether that's flesh or crystal or stuff I can't imagine. You would have to recognize them as people from their minds. And even their minds wouldn't work just like ours do. But anything that lives and thinks and knows itself and doesn't want to die, it's sad, Draco, it's sad if that person has to die, because it doesn't want to. Compared to what might be out there, every human being who ever lived, we're all like brothers and sisters, you could hardly even tell us apart. The ones out there who met us, they wouldn't see British or French, they wouldn't be able to tell the difference, they'd just see a human being. Humans who can love, and hate, and laugh, and cry; and to them, the ones out there, that would make us all as alike as peas in the same pod. They would be different, though. Really different. But that wouldn't stop us, and it wouldn't stop them, if we both wanted to be friends together."

Harry raised his wand then, and Draco turned, and looked away, as he had promised; looked toward the stone floor and stone wall in which the door was set. For Draco had promised not to look, and not to tell anyone of what Harry had said, or anything at all of what happened here this night, though he didn't know why it was to be so secret.

"I have a dream," said Harry's voice, "that one day sentient beings will be judged by the patterns of their minds, and not their color or their shape or the stuff they're made of, or who their parents were. Because if we can get along with crystal things someday, how silly would it be not to get along with Muggleborns, who are shaped like us, and think like us, as alike to us as peas in a pod? The crystal things wouldn't even be able to tell the difference. How impossible is it to imagine that the hatred poisoning Slytherin House would be worth taking with us to the stars? Every life is precious, everything that thinks and knows itself and doesn't want to die. Lily Potter's life was precious, and Narcissa Malfoy's life was precious, even though it's too late for them now, it was sad when they died. But there are other lives that are still alive to be fought for. Your life, and my life, and Hermione Granger's life, all the lives of Earth, and all the lives beyond, to be defended and protected, EXPECTO PATRONUM!"

And there was light.

Everything turned to silver in that light, the stone floor, the stone wall, the door, the railings, so dazzling just in the reflection that you could hardly even see them, even the air seemed to shine, and the light grew brighter, and brighter, and brighter -

When the light ended it was like a shock, Draco's hand went automatically to his robe to bring out a handkerchief, and it was only then that he realized he was crying.

"There is your experimental result," Harry's voice said quietly. "I really did mean it, that thought."

Draco slowly turned toward Harry, who had lowered his wand now.

"That, that's got to be a trick, right?" Draco said. He couldn't take many more of these shocks. "Your Patronus - can't really be that bright -" And yet it had been Patronus light, once you knew what you were looking at, you couldn't mistake it for anything else.

"That was the true form of the Patronus Charm," Harry said. "Something that lets you put all your strength into the Patronus, without hindrance from within yourself. And before you ask, I did not learn it from Dumbledore. He does not know the secret, and could not cast the true form if he did. I solved the puzzle for myself. And I knew, once I understood, that this spell must not be spoken of. For your sake, I undertook your test; but you must not speak of it, Draco."

Draco didn't know any more, he didn't know where the true strength lay, or the right of things. Double vision, double vision. Draco wanted to call Harry's ideals weakness, Hufflepuff foolishness, the sort of lie that rulers told to placate the populace and that Harry had been silly enough to believe for himself, foolishness taken seriously and raised up to insane heights, projected out onto the stars themselves -

Something beautiful and hidden, mysterious and bright -

"Will I," whispered Draco, "be able to cast a Patronus like that, someday?"

"If you always keep seeking the truth," Harry said, "and if you don't refuse the warm thoughts when you find them, then I'm sure you will. I think a person could get anywhere if they just kept going long enough, even to the stars."

Draco wiped his eyes with his handkerchief again.

"We should go back inside," Draco said in an unsteady voice, "someone could've seen it, all that light -"

Harry nodded, and moved to and through the door; and Draco looked up at the night sky one last time before he followed.

Who was the Boy-Who-Lived, that he was already an Occlumens, and could cast the true form of the Patronus Charm, and do other strange things? What was Harry's Patronus, why must it stay unseen?

Draco didn't ask any of those questions, because Harry might have answered, and Draco just couldn't take any more shocks today. He just couldn't. One more shock and his head was going to just fall right off his shoulders and go bounce, bounce, bounce down the corridors of Hogwarts.

They'd ducked into a small alcove, instead of going all the way back to the classroom, at Draco's request; he was feeling too nervous to put it off any longer.

Draco put up a Quieting barrier, and then looked at Harry in silent question.

"I've been thinking about it," Harry said. "I'll do it, but there are five conditions -"

"Five?"

"Yes, five. Look, Draco, a pledge like this is just begging to go terribly wrong somehow, you know it would go wrong if this were a play -"

"Well, it's not!" Draco said. "Dumbledore killed Mother. He's evil. It's one of those things you talk about that doesn't have to be complicated."

"Draco," Harry said, his voice careful, "all I know is that you say that Lucius says that Dumbledore says he killed Narcissa. To believe that unquestioningly, I have to trust you and Lucius and Dumbledore. So like I said, there are conditions. The first one is that at any point you can release me from the pledge, if it no longer seems like a good idea. It has to be a deliberate and intended decision on your part, of course, not a trick of wording or something."

"Okay," said Draco. That sounded safe enough.

"Condition two is that I'm pledging to take as an enemy whoever actually did kill Narcissa, as determined to the honest best of my ability as a rationalist. Whether that's Dumbledore, or someone else. And you have my word that I'll exercise my best ability as a rationalist to keep that judgment honest, as a question of simple fact. Agreed?"

"I don't like it," said Draco. He didn't, the whole point was to make sure Harry never went with Dumbledore. Still, if Harry was honest, he'd catch on to Dumbledore soon enough; and if dishonest, he'd already broken his word... "But I'll agree."

"Condition three is that Narcissa has to have been burned alive. If that part of the story turns out to be something exaggerated just to make it sound a little worse, then I get to decide for myself whether or not to still go through with the pledge. Good people sometimes have to kill. But they don't ever torture people to death. It's because Narcissa was burned alive that I know whoever did that was evil."

Draco kept his temper, barely.

"Condition four is that if Narcissa got her own hands dirty, and, say, Crucioed someone's child into insanity, and that person burned Narcissa for revenge, the deal might be off again. Because then it was still wrong for them to burn her, they still should've just killed her without pain; but it wasn't evil the same way as if she was just Lucius's love who never did anything herself, like you said. Condition five is that if whoever killed Narcissa was tricked somehow into doing it, then my enemy is whoever tricked them, not the person who was tricked."

"All this really sounds like you're planning to weasel out of it -"

"Draco, I won't take a good person as an enemy, not for you or anyone. I have to really believe they're in the wrong. But I've thought about it, and it seems to me that if Narcissa didn't do any evil with her own hands, just fell in love with Lucius and chose to stay his wife, then whoever burned her alive in her own bedroom isn't likely to be a good guy. And I'll pledge to take as my enemy whoever made that happen, whether it's Dumbledore or anyone else, unless you deliberately release me from that pledge. Hopefully that won't go wrong the way it would if this were a play."

"I'm not happy," said Draco. "But okay. You pledge to take my mother's murderer as your enemy, and I'll -"

Harry waited, with a patient look on his face, while Draco tried to make his voice work again.

"I'll help you fix the problem with Slytherin House hating Muggleborns," Draco finished in a whisper. "And I'll say it was sad that Lily Potter died."

"So be it," said Harry.

And it was done.

The break, Draco knew, had just widened a little more. No, not a little, a lot. There was a sensation of drifting away, of being lost, further and further from shore, further and further from home...

"Excuse me," Draco said. He turned away from Harry, and then tried to calm himself, he had to do this test, and he didn't want to fail it from being nervous or ashamed.

Draco raised his wand into the starting position for the Patronus Charm.

Remembered falling from his broomstick, the pain, the fear, imagined it coming from a tall figure in a cloak, looking like a dead thing left in water.

And then Draco closed his eyes, the better to remember Father holding his small, cold hands in his own warm strength.

Don't be frightened, my son, I'm here...

The wand swung up in a broad brandish, to drive the fear away, and Draco was surprised at the strength of it; and he remembered in that moment that Father wasn't lost, would never be lost, would always be there and strong in his own person, no matter what happened to Draco, and his voice cried, "Expecto Patronum!"

Draco opened his eyes.

A shining snake looked back at him, no less bright than before.

Behind him, he heard Harry exhale a breath, as though in relief.

Draco gazed into the white light. It seemed he wasn't lost completely, after all.

"That reminds me," said Harry after a while. "Can we test my hypothesis about how to use a Patronus to send messages?"

"Is it going to surprise me?" said Draco. "I don't want any more surprises today."

Harry had claimed that the idea wasn't all that strange and he didn't see how it could possibly shock Draco in any way, which made Draco feel even more nervous, somehow; but Draco could see how important it was to have a way of sending messages in emergencies.

The trick - or so Harry hypothesized - was wanting to spread the good news, wanting the recipient to know the truth of whatever happy thought you'd used to cast the Patronus Charm. Only instead of telling the recipient in words, the Patronus itself was the message. By wanting them to see that, the Patronus would go to them.

"Tell Harry," said Draco to the luminous snake, even though Harry was standing only a few paces away on the other side of the room, "to, um, beware the green monkey," this being a sign from a play Draco had once seen.

And then, just like at King's Cross station, Draco wanted Harry to know that Father had always cared for him; only this time he didn't try to say it in words, but wanted to say it with the happy thought itself.

The bright snake slithered across the room, looking more like it was slithering through the air rather than the stone itself; it got to Harry after traveling that short distance -

- and said to Harry, in a strange voice that Draco recognized as how he himself probably sounded to other people, "Beware the green monkey."

"Hsssss ssss sshsshssss," said Harry.

The snake slithered back across the floor to Draco.

"Harry says the message is received and acknowledged," said the shining Blue Krait in Draco's voice.

"Huh," Harry said. "Talking to Patronuses feels odd."

...

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...

...

"Why are you looking at me like that?" said the Heir of Slytherin.

Aftermath:

Harry stared at Draco.

"You mean just magical snakes, right?"

"N-no," said Draco. He was looking rather pale, and was still stammering, but had at least stopped the incoherent noises he'd been making earlier. "You're a Parselmouth, you can speak Parseltongue, it's the language of all snakes everywhere. You can understand any snake when it talks, and they can understand when you talk to them... Harry, you can't possibly believe you were Sorted into Ravenclaw! You're the Heir of Slytherin!"

...

...

...

...

...

"SNAKES ARE SENTIENT?"