And then Jones mentioned that the cavern's entrance was actually at the base of the Falls. The others weren't terribly impressed that he had kept that detail to himself.
Their first concern was convincing Kevlin not to beat Jones to death, a task made all the harder when Lennox started to come around to the idea. Ultimately, cooler heads prevailed, and it was decided that Jones could live. For the moment.
The group then focused their attention on how best to descend the falls. Kevlin's suggestion of throwing Jones off the cliff to gauge its height was rejected as impractical.
I figured that things had been going (relatively) smoothly for our plucky adventurers, so why not throw a wrench in the gears?
Now I just need to figure out how they'll overcome this problem. Writing by the seat of your pants can be challenging when you purposefully make it more difficult for yourself. Hopefully I can come up with something by tomorrow.