With anger and desperation driving him, the Doctor worked harder and faster than he had in a long, long time. He refused - absolutely refused - to let the daleks get away from him this time. It didn't matter how many times he would be forced to make this impossible decision - as long as it meant blasting all of those hateful metal robots out of time and space for good, then he was damned well willing to take the risk of losing other innocent lives.

Timelines were converging behind his eyes and spelling out a chilling tale of death and desolation, but he blinked hard and refused to focus on them as he continued coaxing the delta wave into existence. Still, he felt every loss as a stabbing pain against his hearts, knowing that innocent human lives were coming to an end all around him and that there was nothing that he could do to save them.

He was so desperately broken and hopeless by the time that the daleks finally reached Floor 500 that he had been entirely prepared to blow the detonator for the delta wave. His hands were on the handle, ready to erase the entire fleet from existence once and for all - even if it meant taking half of the earth and himself with it.

But just as the Doctor was about to resign himself to his own gloomy end, he thought of Rose. If all had gone according to plan, the TARDIS would have taken her home to her own time on the earth below. He wondered how long it would take her to give up and say goodbye to him - for he had no doubt that she would spend quite a lot of time railing against his self-sacrificing attempt to save her life and stubbornly refuse to give up on that enduring sense of hope that she seemed to carry within her like an eternal flame.

Would she ever make up with Mickey? Would she finally get her normal, human life? Did she have descendants somewhere down there on that smoky, doomed world below? Did the memory of him live on in her grandchildren's grandchildren? Would she tell them stories of the mad old alien who took her away in his spaceship and risked everything just so that she might have the chance to live?

Suddenly, the answer was so very clear that the Doctor wondered why he had spent so much time bothering with the delta wave at all.

"Coward or killer?" the dalek emperor had asked him.

"Coward," he replied simply, knowing that it could never be any other answer - not now, not ever. "Any day." Because as long as there were innocent lives to save, as long as the Doctor was still breathing, as long as there was still time - no matter how short - he wouldn't give up on hope. He had learned that much, at least, from her.

Suddenly, there was a whisper in his mind and he began to wonder if he had somehow willed her into existence with the sheer force of his own desire. But as the whisper grew in volume and intensity, the Doctor immediately began to realize that something was wrong.

The TARDIS materializing behind him immediately caught the attention of every dalek in the room, so he didn't bother to spare a thought for them as he whirled around and hesitantly embraced the warm, golden sensation of his ship as their mental connection was suddenly reestablished.

What ...? But the rest of his question was silenced as the police box doors swung open and a shadow surrounded in the bright yellow light of time stepped out.

The song filling the Doctor's head sounded like his TARDIS, but it was different somehow. The melody was more organized and focused than it usually was. There was something more in it, too - something he had never encountered before.

He blinked once and suddenly Rose was standing before him, looking oddly ephemeral and hazy around the edges, but it was absolutely, undoubtedly her. Excitement and fear warred within the Doctor as he stared up at her, open-mouthed and completely lost for words.

"I looked into the TARDIS, and the TARDIS looked into me," she explained, her voice oddly monotone and ringing with time.

A sudden sense of relief rushed over him and it took the Doctor longer than it should have to realize that it wasn't coming from him - it was coming from her.

Rose, no ... he thought desperately.

But there was a profound sense of peace about her that she was pouring into his mind in waves like a loving caress. All is as it should be, her mind insisted. The Doctor had a brief flash in his mind's eye of timelines converging once more and he understood that this was always going to happen - there was never any other way.

How are you doing this? he demanded, knowing full well that she shouldn't be able to speak mind-to-mind with him like this.

His question was answered with nothing more than an overwhelming, crushing wave of love and devotion and the low, echoing howl of a lone wolf ringing in his head. It didn't make much sense, but understanding washed over him anyway. Rose hadn't just looked into the TARDIS - the vortex was a part of her now, seeping into every cell of her body and changing her into something new.

She wasn't Rose Tyler anymore - or, at least, that wasn't all that she was (as though Rose Tyler could ever just be one thing). She was the Bad Wolf - something different and strange and so very, very wrong that it had all of the Doctor's time senses screaming a red alert.

"I can see everything. All that is, all that was, all that ever could be ..." she went on evenly, as though she hadn't just ended the entire Time War with a single thought. Did she even know what she was doing? How much of this was Rose and how much of it was the Bad Wolf?

The Doctor reached out mentally in an attempt to feel out her mind, but time was burning so brightly within her that it was like trying to look directly into the heart of a sun. But buried somewhere deep beneath it all he could just manage to make out one small, desperate cry for help.

"My head ..." she sobbed weakly.

"Come here."

"It's killing me ..."

"I think you need a Doctor."

If she had been Rose in that moment, she would have laughed or rolled her eyes at him in a teasing, long-suffering way.

Oh, please, let this work ... the Doctor begged silently as he took her hands in his and slowly drew her near. Please, just let me see her smile again ...

Rose's eyes were glowing gold as the Wolf in her swelled and the bright light threatened to swallow them both whole. The sweet song of time was beckoning the Doctor forward, luring him in and urging him closer.

He obeyed the call of both time and Rose - just as he always did - and leaned forward to accept the precious, dangerous gift that had been placed before him. He hadn't intended for it to be a kiss, but as his lips melted slowly against hers, he realized that it could never have been anything else. This, too, was destined to happen across all causalities of time and space.

It was all over far too soon, but as the power of time slowly drained out of her, the Doctor knew that he needed to break his connection with Rose in order to preserve her from the storm of fire that was currently hurtling through his own mind. He laid her on the ground as gently as possible while wars and life and death played out before his eyes more vividly than he had ever seen it before.

The Doctor saw the entirety of his long life - including days that were yet to come - stretched out from his brith and into eternity, spread out across the stars. And through all of it was Rose - though he couldn't be certain if it was really her or the Wolf, since it seemed that this new, separate creature now bore her likeness throughout all of history and the future.

There was a lingering mental embrace and a quiet promise of, Never alone ... my Doctor ... forever ... before the last of the vortex left him and the heart of the TARDIS was restored. The warmth and love and peace of that promise was so convincing that the Doctor very nearly believed it as he watched his ship's doors close and silence reigned on Floor 500 once more.

The TARDIS's mental link settled into familiar solidity in his mind once more - echoing the strange promise in his thoughts and refusing to allow him to ignore it. He wearily welcomed her return and pushed his many lingering questions aside as he bent over Rose's still form below him.

Her breathing was slow and measured, but as the Doctor gently brushed his hand against the side of her face, he could feel her unconscious mind still buzzing with the remaining energy of the time vortex. He projected peace and safety into her thoughts and she let out a soft sigh as her mind stilled and subconsciously reached for him in return.

With the remaining power of the vortex still lingering in her mind, Rose's telepathic powers were even stronger than they normally were, and the Doctor choked on a gasp as she skillfully filled his mind with a sense of contentment. He stared down hard at the slack expression on her sleeping face as he tentatively felt out the edges of her presence in his mind.

She projected a single flash of soft, warm lips, golden, radiating light, and a haunting, familiar melody, before she fell deeper int unconsciousness and her mental signature slowly faded from his mind once more.