The Doctor looks up when Daine nudges him, and manages to pull himself out of his thoughts enough to give her a small smile. "I'll explain later," he says quietly - a phrase he's used quite a few times in his life, which really means he hopes she forgets to ask because he doesn't particularly want to discuss it. He definitely doesn't want to discuss it in front of his two metacrises (Is that the right plural form? There's only ever been one.) though there's a chance he'll have to if they start discussing him and when exactly he comes from. He's only been half paying attention to them until now.