They were, as no doubt was inferred, his two most efficient assistants, Chick Carter and Patsy Garvan, both in disguise, and four o’clock found them seated in the suite assigned them, to which their trunks and other luggage already had been brought. Both then had removed their disguise and were reading the local newspapers, when Nick knocked on the door and was admitted by Patsy. “Well, chief, what’s up?” Patsy eagerly inquired, after closing the door. Nick removed his outside garments and sat down. “We have a hard nut to crack,” he replied. “The case is a serious one, very serious.” “What’s the nature of it?” Chick questioned. “I have been vainly searching the newspapers.” “The case has not reached the newspapers. The facts have been suppressed. They are known by only a few except the persons involved.” Nick then proceeded to tell them of what the case consisted, covering in detail all that he had learned from Chief Welden and Harold Garland. “By Jove, it does look like a hard nut to crack,” Chick agreed, after listening attentively. “It will make a mighty bad mess for the government unless those plans can be quickly recovered. Have you any definite suspicions?” “Not exactly,” Nick replied. “There is one point on which we first must decide.” “Just when and where the dummy portfolio was substituted for the other,” said Chick. “Precisely.” “How can we arrive at that?” “By a process of elimination,” said Nick. “It’s not reasonable to suppose, in view of Garland’s positive assertions, that Captain Backas is guilty of treachery and treason.” “Surely not,” Chick coincided. “Furthermore, he would not have taken the risk that Garland would discover the crime even before leaving, or arriving at the Annapolis station. In that case he would, of course, have instantly attributed the crime to Backas.” “Very true,” Nick nodded. “That alone is enough to confirm Garland’s statements. He undoubtedly had the plans, then, when he started for the station. He rode alone in a taxicab. We can safely assume, then, that he still had his own portfolio when he boarded the train.” “It strikes me, chief, that there is the most likely place for the trick to have been turned,” said Patsy. “I don’t agree with you.” “Why not?” “Because of the publicity on a train,” said Nick. “It would have been exceedingly difficult to steal the portfolio and substitute another without being seen by other passengers. If caught in the act, moreover, escape from a fast-moving train is almost impossible. Crooks shrink from taking such chances. They would have been much more likely to select a safer place for the job.” “That seems reasonable, chief, after all,” nodded Patsy. “It convinced me that Garland is right, which eliminates that part of his journey,” Nick continued. “I think he had his own portfolio up to the time he entered the touring car with the two young ladies.” “But would either of them serve him such a trick?” Chick questioned doubtfully.