"Jack's better off without me." And there was all that guilt again. Of course it would kick in now, definitely the right moment. Right on his way to killing someone. It was his fault and that just made the Doctor even more determined to save him. He did let go of his hand now that he was sure that John was no longer dying. Well. Not right away, at least. Instead he headed back to check on the progress of the science. "And I don't see much reason to be jealous of him anymore now."

He turned around to watch John, both hands on the counter behind him. "Tell me if you feel any change, alright? I... This is going to take a while longer. I'm evolving the cure, making sure it works against the mutated form of the virus. Remember, no falling asleep."