OOC: The "right" door on your map is on your left in the description.
"Why should I care about the safety of the other prisoners? They'd likely let me rot in here. Irregardless, you've clearly made up your mind."
When you return to the flame chamber, you see the door to your left is open. The hobgoblin opened it. Did you close it? Or did it get re-opened?
You can see a dim, very dim bluish light around a corner to the left.
[sblock=IF YOU GO BEYOND THE CORNER]A stairway leads up to an open doorway, the bluish light seems to come from the floor beyond.[/sblock]