A thief named Quen needs a partner for a difficult job. I took her up on the offer. Now that Quen and I are inside the manor, we should search for a way into the treasury.
Once you have used your stealth skills to infiltrate the manor of Fulstrom Homestead and thieves skill to pick the side entrance lock, locate the suspicious bookcase. The bookcase will move to expose a special puzzle lock.
The clue to the lock is on the bookcase top: horn (left), candle (middle), skull (right).