"Very well, so much is clear. These are all facts, not theories. Now, what is the thing that I should do if I were in Cincinnati? I would find out whether one or more of those guests had anything to gain by the death of their host. That done, I would follow the suspected persons. I would have my men find out what each of them had done for a month before the time of the crime. Whoever committed it made some preparation. He did something, too, as you say, in America, to cover up his tracks. Very well. By the keen detective these actions are easily traced. I shall at once place twenty-seven of the best men I know on the track of those twenty-seven persons." "I call that shadowing with a vengeance," remarked the Chicago man. "It will be very easy. The one who has committed the crime is certain, when he is alone in his own room, to say something, or to do something, that will show my detective that he is the criminal. So, gentlemen, if you can tell me who those twenty-seven persons are, in three days or a week from this time I will tell you who gave the poison to Mr. Brenton." "You seem very sure of that," said Speed. "Sure of it? It is simply child's play. It is mere waiting. If, for instance, at the trial Mrs. Brenton is found guilty, and sentenced, the one who is the guilty party is certain to betray himself or herself as soon as he or she is alone. If it be a man who hopes to marry Mrs. Brenton, he will be overcome with grief at what has happened. He will wring his hands and try to think what can be done to prevent the sentence being carried out. He will argue with himself whether it is better to give himself up and tell the truth, and if he is a coward he will conclude not to do that, but will try to get a pardon, or at least have the capital sentence commuted into life imprisonment. He will possibly be cool and calm in public, but when he enters his own room, when his door is locked, when he believes no one can see him, when he thinks he is alone, then will come his trial. Then his passions and his emotions will betray him. It is mere child's play, as I tell you, and long before there is a verdict I will give you the name of the murderer." "Very well, then," said Speed, "that is agreed; we will look you up in a week from now." "I should be pained," said Lecocq, "to put you to that trouble. As soon as I get the report from my men I will communicate with you and let you know the result. In a few days I shall give you the name of the assassin." "Good-bye, then, until I see you again," answered Speed; and with this he and Brenton took their departure. "He seems to be very sure of himself," said Brenton. [Illustration: Jane Morton.] "He will do what he says, you may depend on that." The week was not yet up when Monsieur Lecocq met John Speed in Chicago. "By the look of satisfaction on your face," said Mr. Speed, "I imagine you have succeeded in unravelling the mystery."