"Right," the Doctor said with a sharp nod. "Right, I've avoided far worse than UNIT during a crisis. Who are 'they', do we know?"

He had a feeling this conversation wouldn't end with them and a plan to avoid UNIT and save Jack's daughter. He had a feeling he wasn't going to like what three weeks meant.

Three weeks. That was about how long Martha stayed on Earth before she decided it was time to give up traveling. The Doctor wanted to think that wouldn't happen again. Not with---no, not with Jack.