15. First sign of madness.

The Doctor sat alone in his cell, staring at his hands and trying not to listen to the silence. She was gone. Again.

One of his fingers twitched.

How could he have done this? How could he have let this happen? She had done nothing – absolutely nothing – wrong, and she had died for it. And all because he wouldn't cooperate.

"Hmmmm," a voice said from within the shadows of the cell. "I could learn something from this lot."

The Doctor sighed and hung his head. "Go away."

The Master emerged from the shadows, smirking. "What, now? When things are just getting interesting? I have to admit – I never thought it would come to this: The Oncoming Storm reduced to tears over the death of one, stupid human? She wasn't even old enough to be properly alive."

The Doctor looked up, furious. "Don't you dare, don't you dare say another word about her!"

The Master laughed. "Or what? You'll abracadabra me?"

"Just leave me alone."

The Doctor tried to bury all memories of the Master, hoping that it would drive the apparition away, but if anything it only made the madman laugh harder.

"You won't get rid of me that easily, Doctor. Isn't it obvious? Trying to hide every memory of me just means you think of me more." He placed a hand on his chin in a mockingly philosophical pose. "I wonder what'll happen after all this thinking about her you've been doing…"

The Doctor felt all colour drain from his face. "No, no, no… don't," he mumbled pitifully, hating himself more with every passing minute.

He squeezed his eyes shut on the Master's laughing face and for a moment found himself in soothing darkness. Colours began to swim behind his eyelids due to the force with which he had pressed them together, and began to coalesce.

"No," he muttered, "no, not this, anything but this…"

He found himself softly banging his head on the wall over and over and over again, the soft "thunk, thunk, thunk" drowning out the Master's taunts, though he could still sense the other man's presence. His own hearts beat loudly in his ears: thump-thump thump-thump, thump-thump thump-thump.

Thunk, thunk – thump-thump thump-thump.

THUNK.

The image behind his eyelids gradually merged together; blond, shining hair, a toothy, cheeky grin, eyes so full of life…

He snapped his eyes open in shock and gasped like a man who had just narrowly escaped drowning. To his dismay, she was there, in front of him, beautiful as the day he had first met her. Her expression was one of confused concern.

"Rose…" he reached out to cup her cheek with his hand but caught sight of his fingers and dropped it, trembling with shame and guilt.

"…Doctor? Is that you?"

He stared speechlessly at her.

"Oh come on," the Master drawled condescendingly, "it's not hard to work out. She doesn't recognise you because she was never around long enough to meet this regeneration."

"Who are you?" Rose asked the Master, before turning back to the Doctor. "Wait, am I dead? Oh my God… this can't be heaven."

"Who's to say you're not in hell?" The Master asked, smirking. "He certainly would be."

"He's a good man," Rose countered, sounding for a moment like Jackie. "The best I know."

The Master snorted. "Where have you been living, exactly, another universe?"

The Doctor rose shakily to his feet. "Both of you out. Now."

Rose's concerned expression became one of hurt. "Don't you want to see me?"

"Oh, aren't humans sweet? I think she's actually about to cry…"

The Doctor ignored the Master as best he could, knowing that punching an illusion wouldn't help, though it would make him feel better.

"I wish I could."

Rose frowned in confusion. "What do you mean? I'm right here, Doctor."

"No you're not. You're a hallucination, an illusion." He felt his hearts clench. "And a realistic one, at that."

"But… I remember it all. I remember Canary Wharf, the Daleks… the alternate universe." She grinned. "Coming back."

"And going again," the Doctor couldn't help saying.

Rose's smile slipped. "I worked so hard to get back and you left me there."

The Master tutted. "Oh, Doctor, you didn't."

The Doctor whirled on the Master, finger raised and pointing right in the other man's face. "You… you're not helping! And since you don't know as you weren't there, I left her with my metacrisis and her family!"

"Yes, because abandonment isn't abandonment as long as it's done nicely."

"I did what was best," the Doctor argued. "She wanted her family and to be with me forever, and that's the only way I could do it!"

The Master raised an eyebrow. "And what was wrong with doing it in her original universe?"

"The Laws of Time and Space-"

"The Laws of Time and Space?" The Master repeated incredulously. "Seriously? You're the last of us left, you can rewrite the laws!"

"Last of us?" Rose repeated. "Doctor, is he-"

"Yes."

Rose smiled. "You found someone else! That's brilliant!"

"No it isn't," the Doctor countered. "He's dead now."

"Possibly dead," the Master corrected. "I disappeared, remember?"

The Doctor sighed, feeling all of his energy draining away, and leaned against a wall for support.

That concerned look was back again. "What's wrong?"

"He killed a child."

Rose's jaw dropped. "You what? No," she added suddenly, shaking her head. "No, he didn't. He never would. You're wrong."

"Oh, I think you'll find he did."

"Look, I don't know who you are or how you know the Doctor, but you should know that he doesn't kill people. He doesn't even carry a gun!"

The Doctor remained silent and Rose turned to him.

"Tell him!" she ordered.

The Doctor couldn't even bring himself to open his mouth: his stomach churned and roiled at the memory of what he had done, and he could feel disgust and guilt rising to the back of his throat.

"Doctor?" Rose repeated, starting to sound slightly unsure of herself. "It isn't true, is it?"

The Doctor swallowed and closed his eyes, struggling to breathe.

"Oh my God."

He couldn't bear to look at her, though he opened his eyes. Every time he closed them he saw little Rosie.

"Why?" Rose asked, voice hoarse. "What could have happened to make you kill a child?"

"Well," the Master said, cheerfully mocking voice grating in the suddenly heavy atmosphere, "any number of things. She could have been a brain-washed psychopath… robot…" he shrugged. "Cyberman with major cosmetic surgery and growth problems. But really," he concluded, "from what I hear, she was completely innocent."

The Doctor didn't need to look at Rose to know that her expression was one of shock and horror.

"But he strangled her with his bare hands."

"Doctor?" Rose whispered, taking a step backwards.

The Doctor opened his mouth, closed it, and opened it again. "I couldn't… I couldn't stop, Ro-"

He choked on her name and promptly clamped his mouth shut again, feeling sick.

"Oh!" the Master said, clapping once. "I almost forgot – that's the best bit! She was you." He paused to let that sink in. "Well, child-you."

"But it can't have been me; I'm still alive."

The Master rolled his eyes. "You humans are rubbish at parallel universes. Haven't you worked it out yet? The walls of reality are closed – you're stuck in whichever other one he left you in. It was child-you of this universe that died," he said loudly and slowly.

"I got through once," Rose replied defiantly. "Several times, actually. So what's to say I didn't do it again?"

"I worked it out in the first five minutes," the Master scoffed, ignoring Rose completely. "It's obvious I'm a hallucination – I should be dead or in a Time Lock right now, so how else can I be here?" He nodded his head in the direction of the Doctor. "Granted, I only worked it out because he worked it out and knew that, if I was here, I would have realised what was going on. But let's not quibble on semantics – the fact is, the Doctor knows I'm brilliant, and I am. You, however," he said, looking Rose up and down, "seem quite dim."

"Oi!"

"I've told you," the Doctor snapped, "you're not helping!"

"Oh, but this is all you, Doctor, not me. Everything. You are doing this, and I'm just the poor little projection forced to go along with all of your weird little fantasies."

"No, you're a spell meant to make me reveal secrets or drive me mad."

The Master grinned. "Yes, that too. And I have to say I'm rather enjoying it." He took a step closer to the Doctor. "It's about time you finally saw yourself for what you are."

"I know what I am," the Doctor snarled, finally snapping. "I don't need you to tell me. Do you think," he added, climbing to his feet again, "that I don't know what they call me? I've killed so many I've lost count and brought destruction to so many others. I am drowning," he spat, "in the blood of my species and the tears of those I fail to save. And I remember it all. I dream of it all, over and over and over again, and still I fail! No matter how many times I try, how many times I do it, rethink it, I can't seem to get it right!"

"Doctor," Rose said when the Doctor drew breath to continue. She put a hand on his arm. "You can't save everyone."

"Then what is the point of me?" he asked, remembering what Amy had said as she cried over Rory's charred remains in the Dream World. "I made a promise-"

"An impossible one," Rose interrupted. "You're old, Doctor, old enough to know that people die. You can't always win."

"Then I'm not trying hard enough," he countered.

The Master muttered, "And people think I have a God complex."

The Doctor stood still, breathing heavily. "I could do so much more. I should do so much more. Maybe if I did, the universe would finally let me have some peace."

The Master scoffed. "You can't make a bargain with the universe. Did you learn anything at the Academy?"

"I learnt enough to know what's right," the Doctor shot back.

"And your concept of 'right' included burning Gallifrey, did it?"

"He had no choice," Rose said firmly. "It would have destroyed the universe."

"Is that what you told her, Doctor? Our people could have been great but you burned them before they got there, and you know it!"

"I wish there had been another choice!" The Doctor shouted, becoming more animate now in his anger. "I didn't want to kill them!" Suddenly he broke off in a whisper. "All those children…"

"You're reaching quite a total," the Master said. "Carry on the way you are and you might actually beat me!"

"I can't," the Doctor muttered, running a hand through his hair. "I don't think I can do this anymore…"

"But you can't give up," Rose said. "You can't – don't you remember everything you did, everyone you saved? So many would be dead if you hadn't helped!"

"And so many would still be alive if I had never bothered. You should know better than anyone, Rose, that I'm not perfect. I ruined your life by getting you into danger and then I couldn't even fix it at the end. All I could give you was a consolation prize. And now an alternate version of you – a child – is dead because I can't resist one, simple spell!"

"Spell?" Rose asked. "What spell?"

"Some sort of voodoo this universe has," the Master said.

"It's not voodoo," the Doctor corrected. "I know voodoo, and this is definitely different."

"But… if you were under a spell then you had no choice," Rose pointed out. "You're in a prison, so they obviously have your sonic so you couldn't interrupt the signal. And I'm pretty sure you're not a magician." She snapped her fingers. "It's like the Imperius Curse!"

"The what?" The Master asked disdainfully.

"Harry Potter? The Imperius Curse – it's like magic mind control," Rose explained. "Very hard to resist."

"But not impossible," the Doctor interjected, running a hand through his hair. "I could have thrown it off."

"No," Rose said bluntly, "you couldn't."

"You don't understand," the Doctor said loudly, starting to pace. "It was the Imperius Curse; not like your everyday mind control. This curse leaves you completely lucid – you choose to do what the caster wants, that's the point. I chose to give in and… and…" he stopped in his tracks and stared at the part of the cell where Rosie had once slept. "I killed her."

Rose stared at him. "So it actually is Harry Potter?"

The Master snorted. "Humans. They have worse attention spans than bluebottles."

Rose glared at the Master, but suppressed any questions she might have had. "Anyway," she muttered, "if this is the Harry Potter universe, doesn't that mean there are wizards that are going to be stronger than you, too strong to fight off? Like Voldemort?"

Before the Doctor could react or even understand what had happened, he found himself writhing on the floor in unimaginable pain. When he had finally stopped twitching and flailing, the Doctor lay gasping on the floor, head spinning and throat raw from screaming.

"Ooo," the Master said, yanking the Doctor back to the real world. "A new torture device programmed to start when the trigger word is spoken. Nice." He paused, grinning at the Doctor. "Voldemort."

The Doctor jerked and thrashed again while the Master clapped appreciatively.

"Very clever," the other Time Lord said, walking to where the Doctor lay. "I think this brings new meaning to 'being tortured by the subconscious'. Vol-"

"Shut up!" Rose interrupted, dropping to the Doctor's side.

"You're still here?" The Doctor gasped.

"'Course I am. I'll always be here when you need me."

"Yes," the Master contributed. "You always were focussed on the wrong things."

The Doctor dragged himself into a sitting position. "But you can't be. How could the spell feed off my thoughts of you when I was thinking of something else?"

"Subconscious," the Master reiterated. "Am I the only one in this room with an IQ?"

"Doctor, listen to me," Rose said. "You can't give up. I know you want to, but you can't. Don't interrupt me," she continued when he opened his mouth, "just listen. I know you feel guilty and think that the universe would be better off without you, and I know I can never really understand everything you've gone through. But I know you well enough to say that if you fixate on this you'll forget everything else; the people who are waiting for you, people who need saving, people who can help you. And you'll forget the good that you can do, Doctor, because whatever you think, it is good, and it's more than anyone else has ever done. And if you stay here wallowing in self pity, who's going to save them? What about your friends, all the people you ever cared about? Don't you deserve to see them again?"

The Doctor remained silent, staring at his hands. They shook in his lap, both from the memories and the recent consequences of saying Voldemort's name. Rose lifted his chin so that he had no choice but to look her in the eye.

"Doctor, you need to stay strong, you need to get out of here. Whatever they've got you for – it's not good, and I can't just sit by and watch them destroy you."

She took his hand in hers. It felt so real, so strong and so… there that the Doctor felt a brief flare of hope.

"I'm here to help you," Rose said, smiling. "We'll get out of here."

"Oh for God's sake," the Master interrupted. "You're not real."

"I'm here," Rose countered. "I can touch, think and feel, so don't tell me I'm not real!"

Before the Master could retort, the Doctor heard his cell door slamming open.

"Oh," the Master said, completely forgetting his argument with Rose. "Is it Voldemort?"

The Doctor fell to the ground and writhed, fingers clawing desperately at the stone beneath him as he searched for something to hang onto. Just as he felt himself tipping over into the darkness, the spell was lifted and he was forced back into conscious thought with a groan. Every nerve ending was on fire, his throat was raw and his head was starting to thump uncomfortably.

"Oh dear," said a truly unsympathetic voice. "Did you just say the Lord's name in vain?"