I am too stupid for this, help with first mission

[juan Pablo Navarrete]

I am playing thief DS in expert mode, and I already have the opal and two special objects, but they ask me to get three. I think I found the first one in the old guy´s room, and the other in the poison producer lady´s room. Where is the third object?

[GlasW0lf]

Go up the main stairs in the first section of the mission and head left, then left again. When you get to the study at the end of the corridor search around.

Even more explicit:

In the study, push the large wooden box aside to reveal a hidden passageway onto the balcony. Go right to the end and the last painting is what you're after.