He sets a bottle of silver liquid and a chalice on the desk. "You have one final test."

You look around the room but there's no more doors. Even the door you came in from is gone actually. He watches you bemused, and then gestures to the floor. There's a little trapdoor there.. If it wasn’t for the slight seam around the edge of the door, you probably would have looked right past it. It has a small keyhole in the center, barely noticeable behind the desk.