You’ll need to flip the lever that is hidden in another room on the other side of the major room. This place has a few different “puzzles” inside of them, so I’ll just quickly list them all of and what the solutions are. SOURCE: S (scourge), O (devil), U (misery), R (blight), C (hex), E (curse).BRACCUS: B (bloody), R (rotten), A (thieving), C (very), C (very), U (awful), S (fellow).
You find this hint from talking to the rat right outside the room. So this puzzle is all about giving each word in the respective sentences a symbolic letter.