As luck would have it, Bill, Finn, and Sidd form a trio of unlikely brothers, all feeling as they do a strange compulsion to peer into the pool. They don't feel like they're being tugged so much as they intuit that this would be the right thing to do. The others simply don't give a toss unless they have strong feelings about brackish pools.
Those without compulsions peer about the room. It has four nooks, each with its own hooded robe that have, visible even from a distance, silver-threaded sigils. It also has, more saliently, two mosaics celebrating the exploits of chaos cultists. That old man back at your village was right. Evil does still fester on the accursed hill. The two dude bros at the center are rockin' out.
You can almost hear the steady assault of layered guitar and menacing vocals:
You take a mortal man,
And put him in control
Watch him become a god,
Watch peoples heads a'roll
A'roll...
Just like the Pied Piper
Led rats through the streets
We dance like marionettes,
Swaying to the Symphony...
Of Destruction
Yeah, you could get into that.