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Chapter Thirty—Snake

"Oh, you're a fine one to talk about dangerous decisions." Draco's eyes were on fire, and he moved closer with his teeth bared, as if he were about to repeat the bite he'd given Harry the other day. "It's all very fine for you to enter a house to fight, alone, against someone possessed by the Dark Lord, but Merlin forbid I try something that's guaranteed to save your life! You—"

"It's not guaranteed to save my life!" Harry yelled back, and balled his hands into fists. God, sometimes I feel like I'm back in second year and all I want to do is punch him in his smug face. "You don't know anything about it! You admitted that you didn't understand the magical theory yet, and that Hermione couldn't follow it! You can't expect some abstract technical discussion to soothe—"

"Worries that you should never have in the first place?" Draco surveyed him with a curled lip. "Yes, I can, when I know what I'm doing." He lowered his voice and edged closer. They were in their bedroom, and Harry stood with his back to the door. He felt like stepping away and actually leaning his back against it when he saw the depth of the crazed gleam in Draco's eyes.

"All I'm asking is for you to trust me," Draco said, his voice fragile. "Can you do that? Just trust me."

Harry took a deep breath and rubbed his eyes for a moment. He knew that he really had no right to scold Draco about putting his life in danger. That was the same thing Narcissa had done, and it only proved that she didn't understand the desires that drove Draco. But what Draco described, from what Harry could understand of it, sounded so extreme…

"Explain it to me again," he said, and managed to keep his voice steady. "I can trust you more if I understand more about it."

Draco gave him a soft, adoring smile that caused Harry to blink. He hadn't known it was so easy to defuse Draco's anger.

"That's fair," Draco said. "I wanted you to explain before you went after Finnigan, after all." His eyes sparked for a moment, but luckily he wrestled his indignation back under control and returned to the subject .Harry didn't feel like having an argument they'd already settled. "The Horcrux is attached to your soul. That's only sensible, because the shards of the Dark Lord's soul look for a spirit to bond with, the way the cup did with Finnigan and the way that the diary's spirit did with Weasley."

Harry nodded. That was the part he thought he already understood, but at this point, he decided that hurrying Draco through any part of the explanation was a bad idea. He reached out and took Draco's hand. Draco squeezed his fingers absently, his eyes fixed on some distant abstract realm that only he understood.

"Supposedly," Draco whispered, "the only way to free your soul from the grasp of that piece of the Dark Lord's is for you to die. But I came up with another way. Switching Charms, Harry! The answer was there all along. Substitute someone else's soul for your soul, and of course the piece of the Dark Lord's would become detached."

"But the only way that you could substitute your soul, or someone else's, for my soul is by dying," Harry said. He wondered that Draco hadn't identified the snag in the plan before he had. "I'm not going to allow you to die for me."

Draco shook his head earnestly and brought his free hand up to caress the side of Harry's face. "No. Ordinarily, that might be true. But I'm bonded to the Elder Wand, and no one else has come along yet who could take it away from me. That means the Wand will do all it can to keep me alive."

Harry half-looked away. He couldn't bear to think of the brightness in Draco's eyes dimmed because they had followed this mad plan and then it had turned out not to work. "I don't know what that means."

"It means," Draco whispered, "that we'll switch our souls, not just transfer the Horcrux from one to the other. It'll be like a carousel, Harry. We'll transfer your soul to my body, as my soul goes into yours. The shard of the Dark Lord's spirit will try to latch onto me, but the Elder Wand will rise up to prevent anything else from establishing a bond with me. And then we'll switch again, and your soul will be back with the Horcrux. But its hold will be weakened, and before it can grab you, we'll switch again. And then the Elder Wand can fight it again. Go on long enough like that, and the Horcrux should break apart."

Harry frowned and glanced back at him. "But if it's attached to my soul, then it should come with me, no matter where I go."

Draco shook his head, his smile superior. "That's what I thought at first. But I've looked at the incantations in more detail. And then there's what happened with Weasley. If it was a process of switching souls, then why did her body need to die? No, if he could have, that shade of Tom Riddle would have possessed her, or simply become more real and left her soulless. Like the Dementor's Kiss. It would be less conspicuous. And the same thing happened with the other Horcruxes. When their 'bodies' are destroyed, they're in danger, and seek out another host to possess."

"Dumbledore had another explanation for why Tom Riddle needed to drain Ginny to death," Harry muttered. "Something about life energy—"

Draco sniffed. "Dumbledore hasn't made the study of Switching Charms that I did." He looked so absurdly proud of himself that Harry had to stifle the urge to hug him. He didn't think that would suit Draco's vanity at the moment. "But let's say we're wrong, and the Horcrux does try to cling to your soul. That's why Granger's modifying the Fiendfyre incantation. In this case, we can't use it to destroy the container, because the 'container' is your body, and I have plans for that, thanks." He swept his gaze possessively down Harry's body, lingering on his crotch until Harry had the inevitable reaction, and then glanced away, smirking. "We need something that will burn a soul, and weaken the connection between the Dark Lord's soul and yours if the Switching Charm doesn't work."

Harry blinked slowly. "And you really think this will work?"

Draco leaned forwards and squeezed his wrists, hard enough that Harry winced. "I would never put you in danger if I thought it wouldn't," he said fiercely.

And with that, Harry had to be content. He nodded a little. "When do you intend to practice this?" he asked.

Draco kissed his cheek. "The moment we think we've perfected the incantations. And we're not far from that point right now."

Harry took a deep breath, thinking of the insanely complicated measures this would demand, but nodded again. He would rather that his life be in the hands of his lover and his best friend than anyone else he could think of.

*

Draco narrowed his eyes as he watched the cup crumbling in the basilisk venom Dumbledore had sent and the struggling, screaming spirit slowly fade from sight. Then he glanced sideways at Granger.

"I don't know," she said, pushing sweaty hair out of her eyes. "I don't think we saw everything we needed to. I wish we could make another trial." She grimaced at the swirling basin of venom and shook her head.

"Of course you're going to make other trials, before you put my godson through anything like that."

Draco stifled a sigh and glanced over his shoulder. One of the bad parts of finally coming up with an explanation of what he and Granger planned to do that Harry could understand was that Harry had told other people. Draco knew that Professor Snape would accept it after some intense questioning, and Granger could pacify Weasley's outbursts. But Sirius Black was currently presenting a problem.

He acts like any danger Harry chooses to place himself in is right and good, but that we don't have the right to try and find something that'll work, Draco thought in irritation, and dropped the Impervious Charm he'd been using on his face to shield himself from any stray splashes of basilisk venom. Black complained that he couldn't see Draco's eyes when he used the Charm, and that made him more likely to distrust Draco than he already was. "We don't have another Horcrux," he said. "Except Nagini, and I don't think we'll get close enough to destroy her without also confronting the Dark Lord."

"But Snivellus is contacting Wormtail, isn't he?" Black's eyes narrowed in confusion. "Why can't he just bring the snake along?"

Draco rolled his eyes. Luckily, Granger stepped up then and took over her share of Black-soothing. "The life-debt that Professor Snape is using to persuade Pettigrew is fairly weak," she said. "We don't think it would be enough to make him betray his master and bring Nagini to us, even if he might lose his magic. He's more afraid of V-Voldemort than he is of us." Draco had to grudgingly admire her strength to say the name, even if it was difficult for her.

"I still want another trial," Black said, and folded his arms, as if his mere demand was enough to produce an eighth Horcrux from thin air.

Granger and Draco exchanged a glance of the kind that was becoming familiar to Draco, and which was almost enough to make him call her Hermione. It was their united intelligence against a world of morons, and specifically, one stubborn imbecile.

"We'll do what we can," Draco said. "But no one has ever done this before because the situation has never occurred before. So, for the most part, we're having to rely on theory and reasonable speculation."

Black snapped his teeth shut like the dog he could turn into. "This is Harry's life we're talking about, Malfoy."

Draco opened his mouth, but Granger stepped forwards, her voice shrill. "And do you imagine Harry's life is any less precious to Draco than to you? He's in love with him, Sirius. He wouldn't endanger him on purpose."

Black blinked, apparently so taken off-guard by a Gryffindor defending a Slytherin that he had nothing to say. Draco gaped at Granger himself, and then shut his mouth and tried to look as if he'd expected this. Luckily, Black seemed to be occupied with forcing his slow brain to work, and hadn't noticed Draco's distraction.

"Yes, yes, all right," he muttered. "But I still want another trial. There has to be something you can substitute for a Horcrux."

"We'll try," said Granger, more diplomatic than Draco could have been at the moment, and pushed him out of the room. Then she turned and looked thoughtfully at the basin of venom.

"No," Draco said, reading her expression without effort at this point, they'd spent so many hours working together. "We're not going to scrap our plans for the Fiendfyre and try basilisk venom. We've developed the Fiendfyre almost perfectly. It should work."

Granger sighed. "But we don't know that it will," she said.

Draco sneered at her. "Where's the Gryffindor courage I've heard so much about? You ought to be the one clamoring to use these spells on Harry right now, so that he doesn't have to spend any more time with that Horcrux inside him, poisoning his spirit."

"I know," Granger said. She wrapped her arms around herself. "But I was almost Sorted into Ravenclaw, you know. I keep thinking of all the things that can go wrong, and then I wonder if we're being presumptuous to think that we can do this, where experienced magical theorists would balk."

"Experienced magical theorists don't have the burden of saving the world on their shoulders, either," Draco said shortly, casting a dome spell on the basin of venom so that he could safely pick it up. "We're doing the best we can with limited time and abilities."

Granger made an unhappy noise. Draco ignored her, keeping his eyes on the drifting ashes of the cup as he revised his calculations and his changes to the Switching Charms in his head yet again.

It will work. It has to work.

*

"S-Snape?"

Severus kept a cold expression on his face without effort as he turned around. As much as he would have liked Black to be guilty, knowing that Pettigrew had been the true traitor to the Potters, and the reason Harry had grown up as an orphan and his beloved Lily had died was enough to turn all his hatred against the man.

He snapped his robes over his shoulder in his most intimidating manner as he strode forwards. Pettigrew cowered in the door of Spinner's End. Severus sneered at him, and then waited a moment as Pettigrew carefully checked the wards and spells on the house. He had had to invite the traitor to meet him here, because it needed to be a place that would make it look as if his act was genuine. And it was out of the question to hint at the existence or location of Grimmauld Place, especially if Dumbledore was forced in the next few days to announce that Harry was not hiding at Hogwarts.

"Pettigrew," he said, and the little man winced at the lash of contempt in his voice.

"I just—I came when you summoned me," he whinged, inching closer. "And because you said that I owed you a life-debt. That's not true. Y-you never saved my life. And I won't lose my magic if I defy you."

Severus laughed, and enjoyed the way Pettigrew covered his ears as if he could block the sound out. "Who are you trying to convince? Me? Or yourself?"

Pettigrew straightened and shook his head. "I understand about life-debts," he blustered ridiculously, wagging a finger in Snape's face, "because you owed James one. I know that it only happens when you directly save someone's life, and—"

Severus laughed again, and then whispered, as Pettigrew shut up, "Are you sure of that? Are you absolutely sure? Or did you never hear of the difference between direct and indirect life-debts?"

The little man froze with indecision. Severus prowled a step forwards, lowering his voice until it would sound like a vibration in the bones of his terrified victim. He had deliberately looked up everything he could on life-debts, so that any book Pettigrew read would confirm the truth of what he was saying now. What Pettigrew would probably not think to question was whether he owed Severus a debt at all. "One's actions may save another's life, even if that was not the rescuer's primary intent. If the rescuer takes no notice or has no intention of claiming the debt, it will be allowed to lapse. But I saved your life, Pettigrew. I stopped Black from killing you when he had you cornered in a game of dog and rat in the Gryffindor boys' room. I am sure you remember the moment when my spell changed both of you back to human form? But I retained possession of Black, and allowed you to escape. Do you think you would have survived I had not?"

Pettigrew licked his lips. "But you didn't mean to—"

"And so it is an indirect, rather than a direct, life-debt," Severus said, and gave Pettigrew his best attempt at a winsome smile, from which he shrank more than Severus thought he would have before an outright sneer. "But I am claiming it now. Resist it if you think you can. Risk losing your magic." He paused and assumed an expression of deep thought. "Of course, without the ability to use a wand, you would be rather a burden to your dear Lord and master, wouldn't you?"

Pettigrew's teeth chattered in an agony of indecision. Then he shook his head. "Claim it, then," he said. "I'm calling your bluff, Snape." He turned away as if he would sidle out the door.

"Fool," Severus whispered. "I have already lured you away from your master's side. If you return to him without a convincing story, what do you think will happen to you?"

Pettigrew let out a terrified shriek, one that made him resemble a rat even in human form, and wrapped one arm around his head as if he could shelter himself from the Dark Lord's wrath. Then he whimpered. The whimpering climbed constantly in volume and pitch, whilst Severus folded his arms and waited him out with patience.

Then Pettigrew turned around, his hands clasping and opening in nervous clutches in front of him. "Severus," he said, as if they were old friends. Severus bared his teeth, and Pettigrew slid back, crouching down so that his belly touched the ground. "Snape. Please. You don't know what'll happen to me if you try to make me betray him." He scrabbled at his left arm, where Severus knew the Dark Mark was hidden.

Severus pulled back his own sleeve to reveal his snake-and-skull. Of course Pettigrew knew he was Marked, too, but it couldn't hurt to remind him. "I do know," he said. "I have seen the punishments. And I can imagine what the Dark Lord will do to a follower who is not only disloyal but has no magic."

Pettigrew shut his eyes and shivered. "What do you want me to do?" he whispered.

Severus knew not to push this newfound acquiescence too far. Pettigrew was primarily a coward. If he thought that the threat was close to not being fulfilled at any time, or if he thought that the Dark Lord was more dangerous than Severus, he would turn back the other way and confess everything to the Dark Lord.

"I wish you to help me in my own betrayal," said Severus, and smiled when Pettigrew gasped and looked up at him. "Yes. I have found that my best interests are not served by remaining with Potter. I wish to win clear of this war, and the boy is only interested in dying heroically." It was no effort to curl his lip and call up the scornful tone in his voice, either; he did it by remembering James Potter. "I do not intend to be part of the entourage marching behind him, mindlessly chanting his name as they catapult themselves to an unnecessary martyrdom."

Perhaps it should have worried him, how easily he came up with that story. Surely it would have made Black frantic with fear. But Severus simply accepted the words that spilled out of his mouth, the words he had designed in his mind last night. He had not been a spy for nothing.

Pettigrew nodded slowly. "All right. But what can I do to help that?" A whine had crept back into his voice.

"I have not yet decided whether I wish to remain neutral, or to rejoin the Dark Lord's ranks," Severus said coolly. "Largely because I am not sure which would offer the better chance of survival. I wish you to find out how much the Dark Lord fears the boy. Will he attack him directly? Or will he remain at a distance and let Potter wear himself out by foolishly assuming he can destroy an immortal enemy? If the latter, then perhaps I will rejoin him. If the former, there is a small chance that I might die in the battle, which I wish to avoid."

Pettigrew gnawed his lip nervously. "I don't know, Snape. He doesn't tell me an awful lot anymore. He hasn't confessed his plans to anyone since Lucius and Bellatrix disappeared, I don't think."

Severus fought back a superior smirk. "It may help if you can find out what he means to do with Nagini," he said.

"Nagini?"

"His snake," Severus said, keeping his words as slow and simple as he could. It was a wonder to him how Pettigrew had managed to become a Death Eater and survive amongst the likes of Lucius and Bellatrix. "If he means to keep her by his side, and does not seem worried for her safety, then perhaps he will not engage in battle after all." He paused, pretending to think. "On the other hand, he has always been overconfident of his success where Potter is concerned," he murmured. "Perhaps it would be better if you could learn more details about Nagini herself. She is an unnaturally intelligent snake. Does she seem to think that there is any danger, or does she complacently coil herself around him?"

There. He did not dare command Pettigrew to bring him Nagini yet. That was for later. It was best to establish a spy upon her movements, and slowly lead Pettigrew further and further into betrayal of his Lord.

"And that will fulfill my life-debt?" Pettigrew's nose was twitching as if he had whiskers. Severus could see why his Animagus form was a rat.

"Not completely," Severus said. "That is not fulfilled until I have survived and chosen my side. But it is a beginning."

Pettigrew nodded, looking more confident now. "Nagini is always with Him," he said. "I can observe her easily, since I'm always in attendance on Him, too." For a moment, a strange expression moved over his face, and Severus wondered idly if he was seeing his own doomed future, or the moment when he had condemned himself to this kind of living hell.

Then he shrugged, raised his eyes to Severus's, and said, "When should I bring you the information? And how should I get it to you?"

Severus had been waiting for this. He pulled a paper bird from his robe pocket and waved his wand swiftly above it. It grew in moments into a snowy owl, rather like Harry's. It stretched its parchment wings and hooted twice, then turned glowing amber eyes on Pettigrew, who looked both repelled and fascinated.

"This bird will always find me," Severus said calmly. And it was true; the paper owl would find its way through the wards into Grimmauld Place. "If you try to betray me, then it will grow sharper claws than it has now and hound you to death." That wasn't true, but Pettigrew's face turned the required sickly grey color, and Severus was confident that, for the moment, he has secured his position as a greater threat than the Dark Lord. "Send your messages with it when you are ready."

Pettigrew nodded and scurried out of the house, the paper owl flying just above him.

Severus stood where he was for a moment, gazing around Spinner's End. He had far too many memories associated with this place, and he hated most of them. But surely, he had never thought that someday he would be using it as a meeting place in order to arrange a way to help James Potter's son.

And Lily's. Do not forget her.

I never do, he answered himself, and walked out to his Apparition point, automatically casting detection spells that would find people observing him as he walked. Being a spy had trained him well in more than one way.