The Doctor had been waiting tensely with Romana and the other Doctor, strangely on edge in a console room that looked and felt so much like his own, but wasn't, and he looked up eagerly when he heard the Master return.
With Jack.
"Ah. Hello, Jack." No need to ask which one this was, not having appeared from the depths of this TARDIS. "Coming with us?"
It made sense, he supposed, even though he felt very uncomfortable about the idea of another Jack potentially getting killed because of him.