"I have a piece of important work on hand this evening," he said, "of a private and delicate nature." The detective's look was acquiescent. "Could I get Dennison?" "I think so." Keith stated his case. At the mention of Wickersham's name a slight change--the very slightest--flickered across the detective's calm face. Keith could not tell whether it was mere surprise or whether it was gratification. "Now you see precisely what I wish," he said, as he finished stating the case and unfolding his plan. "It may not be necessary for him even to appear, but I wish him to be on hand in case I should need his service. If Wickersham does not accede to my demand, I shall arrest him for the fraud I have mentioned. If he does accede, I wish Dennison to accompany him to the boat of the South American Line that sails to-morrow morning, and not leave him until the pilot comes off. I do not apprehend that he will refuse when he knows the hand that I hold." "No, he will not. He knows what would happen if proceedings were started," said the detective. "Excuse me a moment." He walked out of the office, closing the door behind him, and a few minutes later returned with David Dennison. "Mr. Keith, this is Mr. John Dimm. I have explained to him the nature of the service you require of him." He looked at Mr. Dimm, who simply nodded his acquiescence. "You will take your orders from Mr. Keith, should anything arise to change his plans, and act accordingly." "I know him," said Keith, amused at the cool professional air with which his old friend greeted him in the presence of his principal. Dave simply blinked; but his eyes had a fire in them. It was arranged that Dennison should precede Keith to the place he had mentioned and order a supper there, while Keith should get the ticket at the steamship office and then follow him. So when Keith had completed his arrangements, he found Dennison at supper at a table near the ladies' entrance, a view of which he commanded in a mirror just before him. Mr. Dimm's manner had entirely changed. He was a man of the world and a host as he handed Keith to his seat. "A supper for two has been ordered in private dining-room 21, for 9:45," he said in an undertone as the waiter moved off. "They do not know whether it is for a gentleman and a lady, or two gentlemen; but I suppose it is for a lady, as he has been here a number of times with ladies. If you are sure that the lady will not come, you might wait for him there. I will remain here until he comes, and follow him up, in case you need me." Keith feared that the waiter might mention his presence. "Oh, no; he knows us," said Dave, with a faint smile at the bare suggestion. Mr. Dimm called the head-waiter and spoke to him in an undertone. The waiter himself showed Keith up to the room, where he found a table daintily set with two covers.