I think the only clue was that all of the other torches in the room were out, with the only lit one being beside the locked door. Earlier in the game you had to light or extinguish torches to open passages, which had more direct clues.
Raze
Thank you Raze.
For the life of me I couldn't figure out how to get that door open so I had to use a hint.
I thought maybe I missed a clue or something.
Now I don't feel so bad about using the hint.
Tsel