four o'clock
Mr. Carter looked very sharply at the gentleman sitting in the easy-chair ; but the closest inspection showed him nothing but a good-looking man , between fifty and sixty years of age , with a determined-looking mouth , half shaded by a grey moustache . `` I 've come to make a few inquiries about a friend of yours , Major Vernon , '' the detective said ; `` Mr. Dunbar , of Maudesley Abbey , who has been missing since four o'clock this morning . '' The gentleman in the easy-chair was smoking a meerschaum . As Mr. Carter said those two words , `` four o'clock , '' his teeth made a little clicking noise upon the amber mouthpiece of the pipe . The detective heard the sound , slight as it was , and drew his inference from it . Major Vernon had seen Joseph Wilmot , and knew that he had left the Abbey at four o'clock , and thus gave a little start of surprise when he found that the exact hour was known to others . `` You know where Mr. Dunbar has gone ? ''