"Rose? What's going on?"
"I killed him…" she choked, crying. "I'm sorry about the mess." Rose gasped as her body went into spasm. She opened her mouth to scream, but nothing came out.
The Doctor grabbed both her arms and shook her, forcing her to keep meeting his terrified gaze.
"Listen to me! You did not kill anyone! I'm here! I'm alive! Rose!" He reached over to the other side of the table, grabbing a strap and pulling it over her, and fixed it clumsily to his side of the bed. He did the same for her legs and wrists, but it didn't keep her much calmer. Pulling the sonic screwdriver from his pocket, the Doctor moved it over Rose's forehead, frowning.
"Rose! Whatever you're doing, you've got to stop. Your head…it's burning, Rose, you're burning!"
"I'm the one who should be dead, not him," she repeated, face screwed up against the pain in her head. "I killed him."
"Rose, listen to me now. Him and me, we're both the same person. I know that's hard to understand, and I should have explained it better, but that's how it is! He isn't dead, not really, he's still here." He pointed at his head as if to demonstrate. "Just a different body, that's all!"
"You're not the same…it's not the same."
"It's more the same than you think. You want to know why I had to do that? Why I had to regenerate? Not because I had to, Rose, because I wanted to. I knew from the start it was going to happen, and I didn't care. Know why?"
Rose shut her eyes, tight closed as though trying to block out what he was saying. Under the Doctor's grip she was still struggling against the straps on the bed.
Keep talking. She doesn't want this…not really…I think?
He realised, then; whatever was in there, in Rose's head, should probably have killed her at least five minutes ago. The TARDIS was keeping it under control.
"I was scared, Rose. I was so frightened. I could see it! I could see the power burning you up from inside out, and it terrified me!" The Doctor swallowed, mentally kicking himself for letting nerves get the better of him even now. "Look, what I'm trying to say is…I did it because I chose to. I did it for you. I did it because I love you, Rose!"
Rose opened her eyes, staring open mouthed at the Doctor. Okay, good, her eyes were brown. Bad, she was still in pain. She obviously hadn't quite given up yet. And something, somewhere, snapped. His knees gave way, and he found himself kneeling beside the bed, reaching up to grasp Rose's hands.
He was crying, he realised, really, full-out crying. Any other time he'd probably have been ashamed of that, but now it didn't seem to matter.
"Rose, don't do this to yourself, please…you didn't kill anyone; I did it – he did it, if that makes more sense to you – because he loved you! So do I. I love you, Rose Tyler, and if you keep on doing this, you really are going to die, and there's going to be nothing I can do, and I couldn't take that, Rose, I just couldn't…please…"