"Hang it all, man," he said, "you are not going to sit there and tell me that Luke de Mountford--the man whom I myself would have chosen as a son-in-law had Lou not forestalled me--that Luke would commit a deliberate murder? In the name of common-sense, Tom, why it's unthinkable! Do you mean to say that you actually believe that Luke, after he left that God-forsaken club, joined his cousin again as if nothing had happened; that he got into a taxicab with him, and poked him through the neck whilst the man was looking another way." "Roughly speaking," assented Sir Thomas, "I believe that's what happened." "And you call yourself a shrewd detective!" exclaimed Colonel Harris hotly. "And you hold the lives of men practically in the hollow of your hand! Why, man! have you forgotten one thing?" he continued, his gruff voice assuming a note of triumph, "the most important in all this damnable business?" "What have I forgotten, Will?" asked the other not at all ruffled by the gallant colonel's sudden tone of contempt. "The weapon, Tom!" "I haven't forgotten the weapon," rejoined Sir Thomas calmly. "Oh, yes, you have! Do you mean to tell me that Luke de Mountford habitually walks about the streets of London with an Italian stiletto in his trousers pocket? for I am told that it was with a thing of that sort that the murder was committed. Or according to you did Luke escort Louisa to a dinner-party with the avowed intention at the back of his mind of committing a murder later on if occasion offered? Did he bring an Italian stiletto from home when he came to meet his fiancée at the Langham Hotel, or did he buy one on the way to the Veterans' Club? Which of these cock-and-bull theories do you hold, Tom?" "Neither," admitted Sir Thomas with a placid smile. "Then," concluded Colonel Harris contemptuously, "you think that Luke was--as I said--in the habit of carrying an Italian stiletto in his trousers pocket?" "No," rejoined the other, still unruffled, "but I know that Luke de Mountford is in the habit of carrying a snake-wood walking stick, which he once bought--years ago--somewhere abroad, and the top of which contains a short pointed dagger which fits into the body of the stick. And what's more you know that stick too, Will; you have often seen it. Are you prepared to swear that Luke hadn't it with him last night?" "He hadn't it with him." "You are prepared to swear to that?" insisted the other earnestly. Colonel Harris was silent. For the first time since the beginning of this long interview he felt as if all the blood in his body was receding back to his heart causing it to beat so wildly that he thought it was about to choke him. The colour fled from his cheeks and the cigar dropped from between nerveless fingers. Swift as lightning a recollection came back to him--a vision of Luke entering the sitting-room of the Langham Hotel with his coat on and his hat and stick in the left hand.