The slim man in evening dress who came softly into the room was a stranger to Monty, who knew most of the prominent figures in the world of criminal detection. And yet his face was in some way familiar. “Captain Newton?” he asked. “That is my name.” Newton rose with a smile. The visitor looked slowly round towards the door through which the footman had gone. “Do your servants always listen at the keyhole?” he asked, in a quiet, measured tone, and Newton’s face went a dusky red. In two strides he was at the door and had flung it open, just in time to see the disappearing heels of the footman. “Here, you!” He called the man back, a scowl on his face. “If you want to know anything, will you come in and ask?” he roared. “If I catch you listening at my door, I’ll murder you!” The man with a muttered excuse made a hurried escape. “How did you know?” growled Newton, as he came back into the room and slammed the door behind him. “I have an instinct for espionage,” said the stranger, and went on, without a break: “I have called for Miss Mirabelle Leicester.” Newton’s eyes narrowed. “Oh, you have, have you?” he said softly. “Miss Leicester is not in the house. She left a quarter of an hour ago.” “I did not see her come out of the house?” “No, the fact is, she went out by way of the mews. My—er”—he was going to say “sister” but thought better of it—“my young friend——” “Flash Jane Smith,” said the stranger. “Yes?” Newton’s colour deepened. He was rapidly reaching the point when his sang-froid, nine-tenths of his moral assets, was in danger of deserting him. “Who are you, anyway?” he asked. The stranger wetted his lips with the tip of his tongue, a curiously irritating action of his, for some inexplicable reason. “My name is Leon Gonsalez,” he said simply. Instinctively the man drew back. Of course! Now he remembered, and the colour had left his cheeks, leaving him grey. With an effort he forced a smile. “One of the redoubtable Four Just Men? What extraordinary birds you are!” he said. “I remember ten-fifteen years ago, being scared out of my life by the very mention of your name—you came to punish where the law failed, eh?” “You must put that in your reminiscences,” said Leon gently. “For the moment I am not in an autobiographical mood.” But Newton could not be silenced. “I know a man”—he was speaking slowly, with quiet vehemence—“who will one day cause you a great deal of inconvenience, Mr. Leon Gonsalez: a man who never forgets you in his prayers. I won’t tell you who he is.” “It is unnecessary. You are referring to the admirable Oberzohn. Did I not kill his brother . . . ? Yes, I thought I was right. He was the man with the oxycephalic head and the queerly prognathic jaw. An interesting case: I would like to have had his measurements, but I was in rather a hurry.” He spoke almost apologetically for his haste.