"i am naturally observant, as you may have remarked, mr. holmes, and i soon had a pretty good plan of the whole house in my head. there was one wing, however, which appeared not to be inhabited at all. a door which faced that which led into the quarters of the tollers opened into this suite, but it was invariably locked. one day, however, as i ascended the stair, i met mr. rucastle coming out through this door, his keys in his hand, and a look on his face which made him a very different person to the round, jovial man to whom i was accustomed. his cheeks were red, his brow was all crinkled with anger, and the veins stood out at his temples with passion. he locked the door and hurried past me without a word or a look.