Harry walked over to the pensieve. He closed his eyes and focused, setting a couple fingertips to his temple. When he drew them away, a silver thread fell from them, and into the pensieve.

"Come on." Harry said softly.

Draco walked over, and they looked into the pensieve.

The Dark Mark glittered green in the sky above the astronomy tower, and sixth year Harry dismounted from the broom just after Dumbledore.

"What does it mean?" Memory Harry asked, looking up at the mark. "Is it the real mark? Has someone definitely been- Professor?"

"Go and wake Severus," Dumbledore said, clutching the cursed hand to his chest. "Tell him what has happened and bring him to me. Do nothing else, speak to nobody else, and do not remove your cloak. I shall wait here."

"But-"

"You swore to obey me, Harry. Go!"

Memory Harry hurried over to the door of the spiral staircase.

"I'm under an invisibility cloak." Harry explained to Draco. "You can kind of see, since it's my memory."

They heard footsteps at the other side of the door, and Dumbledore gestured for memory Harry to retreat. The door burst open, and from here, the two could see Draco Malfoy with his wand raised. "Expelliarmus!"

Dumbledore's wand went flying in an arc over the ramparts he stood against, his face pale white, though showing no sign of panic or distress. "Good evening, Draco."

Malfoy stepped forward, glancing around quickly to check that he and Dumbledore were alone. His eyes fell upon the second broom. "Who else is here?"

"A question I might ask you. Or are you acting alone?"

Malfoy's pale eyes shifted back to Dumbledore. "No," He said. "I've got backup. There are Death Eaters here in your school tonight."

Draco shifted uncomfortably beside Harry.

"Well, well." Dumbledore said, like Malfoy was showing him an ambitious homework project. "Very good indeed. You found a way to let them in, did you?"

"Yeah," Malfoy said, breathing hard. "Right under your nose and you never realized!"

"Ingenious." Dumbledore said. "Yet... Forgive me, where are they now? You seem unsupported."

"They met some of your guards. They're having a fight down below. They won't be long... I came on ahead. I- I've got a job to do."

"Well, then, you must get on and do it, my dear boy." Dumbledore said softly.

There was silence within the memory. In the pause, Draco spoke. "Harry. What is this?"

"Just a moment more." Harry told him.

Malfoy stared at Dumbledore, who smiled, even as they heard sounds of a distant fight.

"Draco, Draco... You are no assassin." Dumbledore said.

Understanding dawned on Draco, and he sucked in a breath.

"How do you know what I am?" Malfoy snapped. "You don't know what I'm capable of. You don't know what I've done!"

"Oh yes, I do," Dumbledore said. "You almost killed Katie Bell and Ronald Weasley. You have been trying, with increasing desperation, to kill me all year. Forgive me, Draco, but they have been feeble attempts... So feeble, to be honest, that I wonder whether your heart has been really in it."

Draco's head snapped to look at Harry. He was met with a somber, understanding... and nearly kind expression.

"It has been in it!" Malfoy said vehemently. "I've been working on it all year, and tonight-"

Somewhere below in the castle, there was a muffled yell. Malfoy stiffened and glanced over his shoulder.

"Somebody is putting up a good fight." Dumbledore said conversationally. "But you were saying... Yes, you have managed to bring Death Eaters into my school, which, I admit, I thought impossible... How did you do it?"

Malfoy said nothing. He was still listening to the fight below.

"Perhaps you ought to get on with the job alone." Dumbledore suggested. "What if your backup has been thwarted by my guard? As you have perhaps realized, there are members of the Order of the Phoenix here tonight too. And after all, you don't really need help... I have no wand at the moment... I cannot defend myself."

Malfoy stared at him.

"I see." Dumbledore said kindly. "You are afraid to act until they join you."

"I'm not afraid!" Malfoy snarled, though he still made no move against Dumbledore. "It's you who should be scared!"

"But why? I don't think you will kill me, Draco. Killing is not nearly as easy as the innocent believe... So tell me, while we wait for your friends, how did you smuggle them in here? It seems to have taken you a long time to work out how to do it."

Malfoy looked like he was fighting down the urge to shout, or vomit. He gulped and took several deep breaths, his wand pointed at Dumbledore's heart. "I had to mend that broken Vanishing Cabinet that no one's used for years. The one Montague got lost in last year."

"Ah." Dumbledore's sigh was half a groan. "That was clever... There is a pair, I take it?"

"In Borgin and Burkes," Malfoy said, "And they make a kind of passage between them. Montague told me that when he was stuck in the Hogwarts one, he was trapped in limbo but sometimes he could hear what was going on at school, and sometimes what was going on in the shop, as if the cabinet was traveling between them, but he couldn't make anyone hear him... In the end, he managed to Apparate out, even though he'd never passed his test. He nearly died doing it. Everyone thought it was a really good story, but I was the only one who realized what it meant- even Borgin didn't know- I was the one who realized there could be a way into Hogwarts through the cabinets if I fixed the broken one."

"Very good," Dumbledore murmured. "So the Death Eaters were able to pass from Borgin and Burkes into the school to help you... A clever plan, a very clever plan... And, as you say, right under my nose."

"Yeah." Malfoy said. "Yeah, it was."

"But there were times," Dumbledore went on, "Weren't there, when you were not sure you would succeed in mending the cabinet? And you resorted to crude and badly judged measures such as sending me a cursed necklace that was bound to reach the wrong hands... Poisoning mead there was only the slightest chance I might drink..."

"Yeah, well, you still didn't realize who was behind that stuff, did you?" Malfoy sneered, as Dumbledore slid a little down the ramparts, the strength in his legs apparently fading.

"As a matter of fact, I did." Dumbledore said. "I was sure it was you."

"Why didn't you stop me then?" Malfoy demanded.

"I tried, Draco. Professor Snape has been keeping watch over you on my orders-"

"He hasn't been doing your orders, he promised my mother-"

"Of course that is what he would tell you, Draco, but-"

"He's a double agent, you stupid old man, he isn't working for you, you just think he is!"

"We must agree to differ on that, Draco. It so happens that I trust Professor Snape-"

"Well, you're losing your grip, then!" Malfoy sneered. "He's been offering me plenty of help- wanting all the glory for himself, wanting a bit of the action- 'What are you doing?' 'Did you do the necklace, that was stupid, it could have blown everything'. But I haven't told him what I've been doing in the Room of Requirement, he's going to wake up tomorrow and it'll all be over and he won't be the Dark Lord's favorite anymore, he'll be nothing compared to me, nothing!"

"Very gratifying. We all like appreciation for our own hard work, of course. But you must have had an accomplice, all the same someone in Hogsmeade, someone who was able to slip Katie the- the- ah." Dumbledore closed his eyes again and nodded. "...Of course... Rosmerta. How long has she been under the imperius curse?"

"Got there at last, have you?"

There was another yell from below, louder than the last. Malfoy looked over his shoulder nervously. Draco's eyes flicked in the direction, but returned to watch his past self, well, past from Harry's perspective.

"So poor Rosmerta was forced to lurk in her own bathroom and pass that necklace to any Hogwarts student who entered the room unaccompanied? And the poisoned mead... Well, naturally, Rosmerta was able to poison it for you before she sent the bottle to Slughorn, believing that it was to be my Christmas present... Yes, very neat, very neat... Poor Mr. Filch would not, of course, think to check a bottle of Rosmerta's. Tell me, how have you been communicating with Rosmerta? I thought we had all methods of communication in and out of the school monitored."

"Enchanted coins." Malfoy said. "I had one and she had the other, and I could send her messages-"

"Isn't that the secret method of communication the group that called themselves Dumbledore's Army used last year?" Dumbledore asked, his voice light and conversational, though he slipped down another inch as he spoke.

"Yeah, I got the idea from them." Malfoy said. "I got the idea of poisoning the mead from the mudblood Granger as well, I heard her talking in the library about Filch not recognizing potions."

"Please do not use that offensive word in front of me." Dumbledore said.

"You care about me saying 'mudblood' when I'm about to kill you?"

"Yes, I do," Dumbledore said, his feet sliding to keep himself upright. "But as for being about to kill me, Draco, you have had several long minutes now, we are quite alone, I am more defenseless than you can have dreamed of finding me, and still you have not acted..."

Malfoy's mouth contorted as though he'd tasted something bitter.

"Now, about tonight," Dumbledore went on, "I am a little puzzled about how it happened... You knew that I had left the school? But of course, Rosmerta saw me leaving, she tipped you off using your ingenious coins, I'm sure..."

"That's right. But she said you were just going for a drink, you'd be back..."

"Well, I certainly did have a drink... And I came back... After a fashion." Dumbledore mumbled. "So you decided to spring a trap for me?"

"We decided to put the Dark Mark over the tower and get you to hurry up here, to see who'd been killed." Malfoy said. "And it worked!"

"Well... Yes and no..." Dumbledore said. "But am I to take it, then, that nobody has been murdered?"

"Someone's dead," Malfoy said. "One of your people... I don't know who, it was dark... I stepped over the body... I was supposed to be waiting up here when you got back, only your Phoenix lot got in the way."

"Yes, they do that." Dumbledore said.

There was a bang, and shouts from below. It sounded as though the fight had moved into the actual staircase.

"There is little time, one way or another." Dumbledore said. "So let us discuss your options, Draco."

"My options!" Malfoy exclaimed. "I'm standing here with a wand- I'm about to kill you-"

"My dear boy, let us have no more pretense about that. If you were going to kill me, you would have done it when you first disarmed me, you would not have stopped for this pleasant chat about ways and means."

"I haven't got any options!" Malfoy said, and he quickly became a shade of sickly pale, as white as Dumbledore. "I've got to do it! He'll kill me! He'll kill my whole family!"

Draco's gaze snapped to Harry again. Harry's expression hadn't changed. It was an expression that made him look much older.

"I appreciate the difficulty of your position." Dumbledore said. "Why else do you think I have not confronted you before now? Because I knew that you would have been murdered if Lord Voldemort realized that I suspected you."

Malfoy winced at the name.

"I did not dare speak to you of the mission with which I knew you had been entrusted, in case he used Legilimency against you." Dumbledore continued. "But now at last we can speak plainly to each other... No harm has been done, you have hurt nobody, though you are very lucky that your unintentional victims survived... I can help you, Draco."

"No, you can't." Malfoy said, his wand hand shaking badly. "Nobody can. He told me to do it or he'll kill me. I've got no choice."

"Come over to the right side, Draco, and we can hide you more completely than you can possibly imagine. What is more, I can send members of the Order to your mother tonight to hide her likewise. Your father is safe at the moment in Azkaban... When the time comes, we can protect him too... Come over to the right side, Draco... You are not a killer."

"But I got this far, didn't I?" He said slowly. "They thought I'd die in the attempt, but I'm here... and you're in my power... I'm the one with the wand... You're at my mercy..."

"No, Draco." Dumbledore said quietly. "It is my mercy, and not yours, that matters now."

Footsteps thundered up the stairs, and Malfoy was shoved as four Death Eaters burst through the door and onto the ramparts.

"Dumbledore cornered!" Amycus cheered, grinning. "Dumbledore wandless, Dumbledore alone! Well done, Draco, well done!"

"Good evening, Amycus." Dumbledore said calmly. "And you've brought Alecto too... Charming."

"Think your little jokes'll help you on your deathbed then?" She jeered.

"Jokes? No, no, these are manners." Dumbledore replied.

"Do it." Fenrir rasped.

"Is that you, Fenrir?"

"That's right. Pleased to see me, Dumbledore?"

"No, I cannot say that I am."

"But you know how much I like kids, Dumbledore." Fenrir rasped, blood trickling down his chin.

"Am I to take it that you are attacking even without the full moon now? This is most unusual... You have developed a taste for human flesh that cannot be satisfied once a month?"

"That's right. Shocks you that, does it, Dumbledore? Frightens you?"

"Well, I cannot pretend it does not disgust me a little." Dumbledore said. "And, yes, I am a little shocked that Draco here invited you, of all people, into the school where his friends live..."

"I didn't." Malfoy breathed. "I didn't know he was going to come-"

"I wouldn't want to miss a trip to Hogwarts, Dumbledore. Not when there are throats to be ripped out... Delicious, delicious... I could do you for afters, Dumbledore." Fenrir said.

"No. We've got orders. Draco's got to do it. Now, Draco, and quickly." The fourth Death Eater said sharply.

"He's not long for this world anyway, if you ask me!" Amycus said, accompanied by his sister's giggles. "Look at him- what's happened to you, then, Dumby?"

"Oh, weaker resistance, slower reflexes, Amycus. Old age, in short... One day, perhaps, it will happen to you, if you are lucky..."

"What's that mean, then, what's that mean? Always the same, weren't yeh, Dumby, talking and doing nothing, nothing. I don't even know why the Dark Lord's bothering to kill yer! Come on, Draco, do it!"

"They've blocked the stairs! Reducto! Reducto!" A voice shouted from below.

"Now, Draco! Quickly!" The fourth said.

Malfoy's hand was shaking so much that he couldn't even aim.

"I'll do it." Fenrir snarled, reaching for Dumbledore.

"I said no!" The fourth shouted, blasting Fenrir with a spell.

"Draco, do it or stand aside so one of us-" Alecto said.

The door burst open, and Snape stood on the rampart. Snape scanned the scene.

"We've got a problem, Snape." Amycus said. "The boy doesn't seem able-"

"Severus..." Dumbledore whispered, pleading.

Snape said nothing, but walked forward, roughly pushing Malfoy out of the way, and gazing at Dumbledore with hatred etched onto his face.

"Severus... Please..."

Harry reached over and grabbed Draco, turning him so he wouldn't see. "Don't look."

"Avada Kedavra!"

A/N

How do you think Draco is going to react to this?

In case you hadn't yet realized, I have been quoting the original books.