(yes -- sorry about forgetting the lava.)

Sorry, I apologize, I'm a bit confused about what's going on in this scene.Qawasha crawled out through muck that quickly turned to dried sand into a stone cell. Soon, Imogen and Weed arrived, with Imogen's whip trailing into a soft impression in the sand.
The room's walls were covered with bas-reliefs showing desert sands swallowing the ruins of civilization. A bas-relief of a robed medusa dominated one wall, wearing a stone necklace with an obsidian pendant and clutching a burning iron brazier. Sand was falling from tiny holes bored into the ten-foot-high ceiling, and they could hear a rumbling noise in the far corner, below the floor, as thick sand began to shudder and shift in that direction.
There, Ussal was struggling to remain free of the sand that flowed toward that corner.
Sure. Easy enough to happen.Sorry, I apologize, I'm a bit confused about what's going on in this scene.
Right. It starts out a tunnel, which turns to muck, then sand.We are in a room full of water and then we swim down into a muddy hole.
No. The hole is near the bottom, but it is in a corner. You crawl through it and back up into sand.Was the water draining into that hole?
Yes! That's right.The mud turns to sand and we climb up and out into a room with sand in it?
Once there, you'd probably suffocate in sand if you tried to go back down (the hole is kinda lost by the time you push your way through the sand, though I suppose it could be attempted now that Imogen's whip is leading that way. It's not really a hole on this side, though - it's simply sand that you pushed your way through.Can we go back out through the same hole, back into the water room?
Lots?The room is stone. How much sand is in the room?
Yes, that's right. There's some other contraption in the far corner that is churning the sand towards it and down, causing the rest to slide in that direction.and is the room angled so we're sliding towards a hole where the sand is being siphoned into?
Burrow would probably be better. Climbing on a surface that is moving downward can be counter-productive.@FitzTheRuke
I think I'm going to use a Wild shape. Since Qawasha fell, how difficult would it be to get to a wall?
I'm waffling between Giant Wolf Spider (I imagine those exist in the jungle!) with a climbing speed, and a Giant Badger (burrow speed). Will the burrow speed be useful?