Maybe they can find a source of water in this particular illusion so he can clean up. His own illusions involved putting props in the tunnels themselves, not a complete scenery change like this; honestly, it's a bit impressive.

"Now there's the real question. It's at least partially based on some kind of rail system, I think. I woke up up top and the place lured me down here with the sound of a woman screaming, and I've been trying to find my way back up ever since." He sighs, crossing her arms as he surveys the familiar scenery.

"I bet you woke up here, too. Try to remember."