Collected from Arsaga:

They're soon fairly deep into the caves, which are anything but even in their design, and the elevation changes often - sometimes abruptly. As it is, they're currently progressing past a chasm, edging their way across a thin ledge, with water running down the other wall of the chasm in a strange, docile waterwall. The chasm's about a metre wide, if that, and drops down into darkness.