[...Ah. So there it is. Asch isn't particularly shocked by the revelation, though he is a bit surprised that Van is being even a little open about it. Trying to gather sympathy from the locals? Using an illness is a tactic he should've expected from Van. Not a single trait the man has is useless or discarded, besides basic human courtesy, maybe.]

He is. The fonons of his body have been poisoned by a miasma from the core of the planet. Without medicine or the right treatment, it's going to kill him.