"Yeah, well. The jealousy passed very quickly for me too. For different reasons, probably." With him it had less to do with him wanting Jack than Jack wanting him. Oh, and - moreover - Rose wanting him, he supposed. But that was all so long ago that it barely seemed real anymore. A lot had changed.

"You have to stay awake, John, you know that. I know how stubborn you are, so don't you dare fall asleep." The Doctor looked at him, swallowing before turning away to look through the microscope again. "That guy had been sick for a while. That won't happen to you. I'm hurrying. I already know what to do, I just have to make this work right for your body. By the 51st century your biological make-up is quite evolved. Good thing generally, not so much in this situation. But I can do it. Just stay with me."