Author's note: anyone who reads fanfiction knows that I own nothing. This started off as a small drabble while I was at work and grew into something much bigger than that. I've uploaded what I have, but I'm not entirely sure the Doctor and Rose are going to let me leave it like this. We shall see. Enjoy!
Looking back, really looking at the moment where he changed the course of their lives forever, he would never be quite sure why he did it. Maybe it was the desperation in her eyes, her hands reaching for him, her golden hair haloing her face as she slipped towards the Void would burn in his mind forever. His fault - all his fault, once again. Jackie would never know how right she was. Rose; brilliant, fantastic Rose, had chosen him over her family, over safety and a normal life, and she would no longer get a chance to choose again. He had killed her, just as surely as he killed his people. She would be swallowed by the Void, her spirit, her essential, well, Rose-ness, would be crushed and changed and destroyed. She would be beyond his reach forever.
He could not bear it. With a mere nanosecond's worth of calculation, the Doctor let go of his hold on the clamp, and pushed off of the wall with all of his might. If he was lucky - very, very lucky - he might just be able to reach her. To grasp her hand. He had to try. He couldn't let her fall away from him without trying to save her. He owed her that, at least. No thoughts were in his head but of Rose. He wondered, briefly, when he had stopped caring only for the overall good and began caring for her instead. A flash of 10 Downing Street, the threat of a missile strike that would save the world but would mean he would lose Rose. Perhaps then. He had been lucky, then.
She saw him, and turned her body to try and grasp his hand, trying to stop her fall as much as possible. She was mouthing something, but he could not hear her over the sound of his hearts hammering in his ears. Time had slowed to a crawl. Every beat of his hearts, of her heart, felt as if it could be their last. Luck was with him today, it seemed. He felt her warm hand in his, and he pulled her towards him with all of his strength. She wrapped her arms around him, like she always did. She clung to him like a lifeline, and he could feel her heartbeat racing in her chest. She was terrified. The overwhelming whiteness of the Void was reflected in her eyes, and he buried his head in her golden hair as they crossed the barrier. What was beyond was unknown, but he found himself unable to care. They would go together.
Rose almost cried with relief when she saw the Doctor leap towards her. He would have a plan - somehow, he would get them out of this. He always had before. Every time the chips had been down, he had somehow pulled off an impossible-seeming scheme and rode to the rescue - sometimes literally. Despite her near unshakeable faith in him, Rose could not rid herself of the little niggle of doubt. That he didn't have a plan, and that his leap towards her was not calculated at all, that they would both simply vanish into the great white expanse behind her, and that would be that. The words the devil had spoken on Krop Tor thundered in her ears, and her stomach plummeted. She had doomed them both. She clamped down on that feeling, willing it away from her. It would cease to matter when they crossed that boundary behind them. Stretching as far as she could, she grasped the Doctor's cool hand in hers, and pulled herself towards him with all of her strength. Buying herself an extra second wrapped in his strong arms before her life was over. Their lives were over. Tears sprang to her eyes, and Rose tangled her fingers in his dark brown hair as she nuzzled her head into his neck. She didn't want to watch. The whiteness overtook them, and the last thing Rose saw was brown pinstripes. She smiled. It was, she considered, a good last thing to see.
The Doctor held the unconscious body of his companion in his arms, as he picked his way carefully through the pure junk that littered the white expanse where they had ended up. He wasn't even sure where "here" was, and was unwilling to assign it a title yet. They were nowhere, really. Outside of time. Everything was white, pure white. The floor, he supposed it was, echoed his footsteps, and there was light coming from somewhere - though he couldn't tell where. He could have been walking on a treadmill, for all he knew. There was no real sense of movement or progress. It would have been completely disorienting had there not been Cybermen and Dalek parts scattered haphazardly around. Literal mountains of debris that he had blown into this space were piled around them. None of them had survived. He was, frankly, surprised that the two of them had. He had supposed, being a Time Lord, that existing in a space that was not governed by time would be problematic - perhaps even explosive - but it seemed that he had fared the journey better than Rose. He glanced down at the girl in his arms, and allowed himself a small, sad smile. She was alive, even if she was unaware of her surroundings. Perhaps it was better that way. Perhaps not. He missed her, oh he missed her. She would have had her warm hand inside of his, trusting him to find a way out. She would have some sort of comment that would focus him. He was unwilling to admit to himself that all he was doing was wandering. He knew, rationally, that there would be no way out of the Void. Especially after losing the TARDIS. His head twinged, as hard as it had the first time he had thought of his missing ship while in this wasteland. His psyche was desperately searching for the psychic connection with his ship. It was gone. Completely gone. He staggered, suddenly overwhelmed by the silence in his head. He panted, staring hard at his scuffed white trainers as he tried to put the world back into perspective. He was reeling, spinning, listless - like a ship caught in a hurricane. The TARDIS, his constant companion for almost a millennium, was just... Missing from his head. No gentle murmur of reassurance, no almost-laughing glow... Nothing. Sweat rolled down his nose. He began compartmentalising as best he was able. Behind several large, locked doors went his loneliness, his despair and his guilt. There would be either be another time and another place for dealing with those, or there would not be. They would not do him any good here.
Shifting Rose in his arms, he plodded on aimlessly. It was not in his nature to readily admit defeat, but it was staring him in the face. They were trapped, and Rose would die. Not for the first time, Gallifrey burned behind his eyes as he took another staggering step forward. Murderer.
After thirty five minutes, six seconds more of aimless wandering, he sat down on the hard white floor, leaning against the body of a Cyberman. He arranged Rose carefully in his lap, balanced between his knees as to better support her. She was still boneless, limp, lifeless. Her breath ghosting against his neck and her faint, thready pulse were the only two signs that Rose was even still alive. He bowed his head, leaning his cheek against her soft hair and settled her more comfortably in his arms. He murmured apologies to her, over and over again half hoping she would hear them and wake. Unconsciously, he rubbed slow circles on her forearm with his thumb. Rose remained still, and he knew it was his fault. All his fault. He stared at the destruction around them, knowing this was no dream but willing himself to wake up all the same. This time, they would find no way out.