Son of a crap.
Just one big dead end.
lil' map from before
Spoiler
Looks like we just explored the rooms to the North of A and B there. So next would be C or D.
Lazarus leads the party back through trying to avoid all the freaky moldy crap and all the way around back towards exit "C". Assuming folks go with him.
SpoilerDo we need another fort save on the way out? If so:
Fort save - (1d20+6)[24]