"Huh." It's not a lot to go on, but it does have the sound of an illness - if one that doesn't function the same way an Earth illness might. What would differentiate it from a curse around here, anyway? He's got research to do, if only to figure out how Noctians see the line between the two.

And a city to get to know, for that matter. All of this will be easier when he knows the place.

"Sounds a little like rabies - get it, and you're probably not getting out alive." He'll need Scully's help with this. He would anyway, but especially if the situation's that medically based. And that means that he's going to have to get her on board with going out after dark in search of answers. "When I lose the leaves, you want to look into it with me?"