You might have missed either the bottle on the floor in one of the dark Hammerite rooms or (more probably) the LC tapestry in the Hammerite area.
For the author (if he's here): I liked the atmosphere of a medieval mansion in a storm and the weather effects were nicely done. One criticism, though - it's better to include a "return back" objective, since now the mission ends when the player has found more than 1800 loot and the Hand. But a lot of people want to try to find all the loot, which is impossible like this (since the mission ends when you're over 1800).