I found the two bags and the ruffian sent me back to the bottom. But I can't find any clues there... Just four objects to see or try to interact with: crevasse, skeleton, mound and alcove (there are some markings on the alcove, but they aren't clickable as separate objects), no spells can be used apart from Float to get back to the surface... I just have no idea whatsoever what to do there.
I'd think that it should be possible to go into the alcove, but it doesn't work - either with Walk or Hand icon.

There are only two bags. You don't need to go back to the chasm. You need to give the ruffian a clue as to how to move forward with the quest.