He was burning. He could feel it in his veins as it spread through his body, eating away his resistance, leaving only sadness in its place. Unnameable sorrow, as was his due.

She was awake. The coward in him had hoped that she'd still be unconscious, eyes closed, hair covering her face when it happened. That he could just slip away, unnoticed, unquestioned. To go before she could look in his eyes and leave the explaining to the man who was going to take his place. To run.

But she had woken up, run a hand over her face, and looked at him with eyes alight, a smile on her beautiful face, not remembering a thing and his hearts clenched. He couldn't do it. He knew he couldn't.

He kept talking, talking about Barcelona and its dogs and how he wanted to take her there. He was laughing - a desperate and exaggerated sound that at any other time would have caught her attention. But right now she just smiled a dazed smile and got up slowly, already coming to him, wanting to hug him, to offer comfort as much as take it - like they always did.

I sang a song and the Daleks ran away. By Rassilon, he was an idiot!

He shook his head and decided to be honest with her. He was going to change and he was damned if he'd leave her without explaining. He flinched as golden light swirled through his blood, pulsing underneath his skin.

To hell with explaining, it was too late for that! Saying goodbye then.

But suddenly the light was burning him up, burning him alive, and she was coming to help and he would have liked nothing better than to let her, to take her in his arms once more and kiss her properly, kiss her without the Time Vortex running through her head. But he couldn't. It was time to go and he couldn't even kiss her goodbye.

"I absorbed all the energy of the Time Vortex and no one's meant to do that. Every cell in my body is dying."

"Well, can't you do something?"

"Yeah, I'm doin' it now! Time Lords have this little trick. It's, er… sort of a way of cheating death. Except… it means I'm gonna change." He tried to explain, tried to make her understand, but he could see it was too much; she wasn't going to accept it in time.

"And I'm not gonna see you again. Not like this, not with this daft old face. And before I go…"

"Don't say that!"

She was panicking now, desperation and fear in her voice, something else he dared not name in her eyes, and he wanted to calm her, to tell her it was going to be okay, to tell her there was nothing she could do, that she had done more than anybody else could have ever done for him already. But there wasn't time.

"Rose! Before I go I just wanna tell you, you were fantastic. Absolutely fantastic! And do you know what? So was I!"

They shared one last smile, one last look that spoke of everything, yet told nothing. And then it was time.

"One more thing… Please don't forget Jack. I… I left him there - on the Gamestation. I shouldn't have done that. Please go back for Jack."

And then he was burning up, every cell screaming, each atom dancing madly in the air with another one, rearranging, expanding, leaving, then coming back - all in a mad swirl that left him in agony. But suddenly there was another feeling - a clearer and calmer one. Pleasant and soothing. Warm lips on his, two hands around his neck and a small, fragile body against his own leather-clad one. Rose!

Stupid, sweet, lovely, idiotic Rose. She couldn't let him go after all; he couldn't make her understand that he wasn't leaving, not really. She was human, very human, impossibly human and yours truly had forgotten. Again.

She wanted him, not some stranger. And the stubborn little ape she was, she wasn't going to back down until she made sure he was safe. But she was going to get killed. She was going to burn up and there was nothing he could do this time. He couldn't move a finger; much less make Rose back away.

He'd regenerate, he'd come back with a new face and a new smile and some new teeth and wear new clothes. But if Rose Tyler died he'd also have a new sadness to carry. One that he couldn't bear.

He tried to tell her, tried to force his lips to open, to get the words out, but it was too late. Something else was already happening - something far more wonderful than regeneration. Rose was inside his mind, and he was inside hers and after a while he couldn't tell where one ended and the other began and it was the most fantastic feeling he had ever experienced. The burning didn't seem important - nothing seemed important now that they were finally made one. Sweet, warm, lovely Rose filled him up entirely, chased away the silence, the loneliness, the emptiness and the guilt. He couldn't let go or deny his love for her anymore. He reached out, made the connection stronger, entwined the strings of their thoughts. It was like a very tight, extremely intimate embrace and all he could feel at the moment was love for this wonderful woman whose last act was to try and save him. He knew she could see it, feel it, know everything that was going on inside his mind, clear as daylight, but he didn't care. He'd have probably tried to go back on it later, had he ever had the chance, but as fantastic as Rose Tyler was she wouldn't have let him. Not that it mattered, since they were both at the end.

The connection was fading, her mind being torn away from his and he panicked. He tried to hang on, to clutch her to him, but she was prying his fingers off, smiling gently, telling him words he couldn't understand, words that soothed his soul nonetheless. He couldn't breathe, was blinded by an absence of light inside, his heart frantically thumping blood around his body, desperately trying to keep him alive. No regeneration felt this way before and he was truly scared. He gasped and tried to force air into his lungs, swaying dangerously on his feet, confused and slowly starting to realize that the reason it all felt so strange was because there would be no regeneration this time. He was going to die.

As the world turned blacker around him he cried out, saying the only word he knew would keep him safe; keep him going a bit longer.

"Rose!"

As he fell down and spiralled into unconsciousness he felt gentle hands catching him, slowing his descent and he smiled. Rose was there. Everything was going to be alright.

Heartbeat. Slow and steady.

Pumping warm blood around his veins.

Fingers tingling. Head pounding.

Air pouring in and out of his lungs.

Heart beating.

One heartbeat.

Just one.

The Doctor sat up suddenly, hitting his head on something sharp and gasped at the realization that he wasn't dead. As the world came to a halt from all the mad spinning it did before, he blinked around in confusion.

He was on the Tardis. In the console room, to be precise. And… they weren't in motion. They were parked somewhere. He got to his feet gingerly, carefully opening the door a crack and found himself staring at hundreds upon hundreds of exposed wires. His own handiwork.

They were back at the Gamestation.

But how? Did that mean Rose wasn't dead after all? And why weren't both of his hearts beating?

He took a shuddering breath and was about to step outside when he heard voices. A man and a woman. Walking towards him. Towards the Tardis. A man and a woman he knew very well. He ran outside and clashed into Jack and Rose, all three of them ending up on the floor, laughing and hugging like children after an exhausting day-trip. He sat up and was about to ask how when Rose shook her head, "Later."

He managed to remain silent for precisely 47 seconds. Rose rolled her eyes while Jack slapped him on the back and wiggled his eyebrows.

He scowled.

Jack and Rose laughed.

Finally, when they were all safely in the console room again, she gave in.

"It was the Bad Wolf."

"I thought that was you, giving yourself reminders to come back and save me."

"It was. But…" She looked a little lost for words and let out a frustrated sigh. "I don't know how to explain it, Doctor, it's like suddenly there was a whole another me in there - a bigger, wilder, more dangerous me that couldn't be contained within this human frame. Like… a wolf wanting to run wild."

He nodded, although he had no idea what she was talking about and remembered that his other heart still wasn't beating.

"What'd happened to me? And how are you still alive?"

She gave a nervous little laugh and bit her lip, looking at Jack. Jack nodded and continued.

"When Rose kissed you," he gave the Doctor a lopsided grin and laughed when the other man's face darkened threateningly, "she took some of the energy of the Time Vortex out of you and put it back into herself. She couldn't withstand it of course, being human, but it was more manageable with the two of you sharing the load."

"I… I knew I was gonna die, Doctor," Rose continued. "I could sense it, feel myself burning. But the memories have also returned - of the first time I looked into the Tardis. After you sent me away."

The words sounded accusatory and the Doctor couldn't quite meet her eyes.

"And… and the Tardis was still trying to help. In her own way. She showed me what I needed to do." She had tears shining in her eyes now and the Doctor was horribly afraid she had sacrificed herself.

"Rose…"

"Shhhh."

She had her hand outstretched towards his torso and he held his breath as it made contact with his chest. She brushed his leather jacket aside and laid her hand on the right side of his jumper - the place where his other heart should have been beating.

"I… I needed another one. Mine was going to give out and I... I was in your mind Doctor. I knew you couldn't bear losing me again." She was crying now, properly crying and the Doctor cursed himself, preparing for the worst news.

"The Tardis showed me how. And… I… I took it."

She whispered the last words like a prayer and didn't meet the Doctor's eyes, sobbing silently. The Doctor's eyes widened and suddenly he understood. He would have laughed out loud if he wasn't so shocked. Relief - pure, undiluted relief swept over his body in waves and he felt he could run all the way to Earth and back. But his mind didn't catch up to his emotions just yet. Working overtime, the Time Lord brain, as always.

"You… have my heart. One of my hearts is beating in your chest."

Rose nodded and cried harder and the Doctor cursed in several languages and took her into his arms gently, glaring at Jack as if he'd be the one to blame for his own stupidity.

"Hush now, love, it's alright."

She whipped her head up, mouth hanging open, wonder in her eyes.

"It is?"

This time the Doctor laughed - a true, crystalline, joyous and whole laugh.

"Sweet, darling, lovely, ignorant Rose."

Her expression changed and she was ready to retort, but he was quicker. He closed the distance between them in one swift step and suddenly his lips were on hers, pressing softly, gently, asking for entrance instead of demanding like he usually did in their verbal matches. She opened herself up to him without hesitation, tongue sliding against his, tasting him, letting him explore her mouth. There was hunger, but it was restrained; desperation, but it was mixed with relief. Devotion, but it was peppered with fear. The cavalcade of emotions he seemed to be able to pour into one kiss made her dizzy and she could hardly do anything but hang on for the ride.

He bit her lower lip lightly, eliciting a surprised little gasp from her, deepening the kiss further, awakening the fire in her belly. She grasped his neck tighter, pressing her body close, showing him that this was exactly what she wanted. A moan escaped him and she smiled against his mouth, one arm dropping to grasp his lapel, the other scraping his head lightly.

It ended all too soon however when he broke the kiss, looking down at her with blue eyes shining, a few stray tears already having escaped their confines. There was something else shining down from them too and she held her breath, waiting for him to speak.

"Rose Tyler. I'm going to take you to so many places! Barcelona? Not the city Barcelona, the planet Barcelona. You'd love it. Fantastic place! They've got dogs with no noses."

She smiled up at him through the tears, and that was all he needed. He didn't need two hearts, he didn't even need the one that was still working to be whole; he just needed Rose Tyler to go with him to the ends of the universe and back.

"But, my heart. Well, yours… What if… What if it gives out?"

She was shy again, all shy and careful and hoping, but not daring to do it too hard.

"Well in that case, I'd say you are going to be just fine."

"How's that?" The corner of her lips were curling up, her tongue poking out a bit and he felt sure that nothing could ever go wrong again. Not while he had Rose.

"You've got yourself a Doctor."

Whiskey coloured eyes met crystalline blue ones and it seemed they didn't need the telepathic link to feel as one this time.

"Erm… Hate to interrupt, but am I still going to be on board? You know, with my strangely returned from the dead self?"

"Don't be daft, of course you're still coming! Isn't that right, Doctor?"

The Doctor smiled and clasped Jack on the back - maybe hitting him a little too hard because he started to cough.

"Course he's comin'. I'm gonna need him to pilot the Tardis when I'm otherwise engaged."

It was Jack who burst out laughing first, but Rose and the Doctor followed closely behind. All their journeys together, all the trials they've faced, the deaths they've seen and left in their wake - it didn't matter. It would sting tomorrow, hurt like an infected wound a week from now, and they'd have to deal with it. But they had each other. The three of them, together. And that was enough. For now and forever.