police, save the inexplicable fact that neither upon Mrs. Barclay's person nor upon that of the victim nor in any part of the room was the missing key to be found. The door had eventually to be opened by a locksmith from Aldershot.
"That was the state of things, Watson, when upon the Tuesday morning I, at the request of Major Murphy, went down to Aldershot to supplement the efforts of the police. I think that you will acknowledge that the problem was already one of interest, but my observations soon made me realize that it was in truth much more extraordinary than would at first sight appear.
"Before examining the room I cross-questioned the servants, but only succeeded in eliciting the facts which I have already stated. One other detail of interest was remembered by Jane Stewart, the housemaid. You will remember that on hearing the sound of the quarrel she descended and returned with the other servants. On that first occasion, when she was alone, she says that the voices of her master and mistress were sunk so low that she could hear hardly anything, and judged by their tones rather than their words that they had fallen out. On my pressing her, however, she remembered that she heard the word David uttered twice by the lady. The point is of the utmost importance as guiding us towards the reason of the sudden quarrel. The Colonel's name, you remember, was James.
"There was one thing in the case which had made the deepest impression both upon the servants and the police. This was the contortion of the Colonel's face. It had set, according to their account, into the most dreadful expression of fear and horror which a human countenance is capable of assuming. More than one person fainted at the mere sight of him, so terrible was the effect. It was quite certain that he had foreseen his fate, and that it had caused him the utmost horror. This, of course, fitted in well enough with the police theory, if the Colonel could have seen his wife making a murderous attack upon him. Nor was the fact of the wound being
