"What?" the Doctor says, his face mirroring her horror. "No, Rose, it was---it's not like that! We just...shared a few memories, she kept a bit of my personality from it, that's why she acted off to you."

He's not explaining himself well, and he feels like pacing or flailing, but that would mean moving away from her, and part of him is terrified to do that, too.

"It's---it's not her fault. I just thought I could help. And it did! It helped, she---trusts me, sort of. Which, in the end, is why the Master must've picked her, too."