"Yes, yes. Hello. You're here." The Doctor flashed his old friend a quick smile. He'd done as he'd been told and sat down, keeping movement to a minimum in the hopes of slowing the poison's spread. He was doing a bit more than that, as well. Time Lords, at least some of them, could manipulate their own biochemistry to a certain degree. He hadn't done this in quite some time, but he was paying much closer attention to the chemical processes in his body than usual, wondering if perhaps he might be able to metabolize the poison in such a way that it might help. So far, no luck, and it was dreadfully difficult to focus when his sense of equilibrium was completely shot.
"Need a bit of help sorting out what's going on," the Doctor managed. "If we can identify the toxin ... well, toxins might be more accurate ... we might be able to do something. What should I call you, by the way? The other you, the you I know, he likes to be called the Master. You don't like to be called the Master, do you? Are we still going by school names? Thete and Koschei and all of that? Or did you pick something else? Like, oh, I don't know ... Not the Master?"