The fact that a crime has been committed is generally apparent, though there have been cases in which the determination of that point requires as much skill as the whole remainder of the operation. Such was the case in the detection of Mrs. Pattmore's murder, related in my story of "The Murderer and the Fortune Teller." The object of a crime is also sometimes obscure, and, where such are the circumstances, the detection of the criminal is apt to be one of the most difficult of all operations. Having once solved these two difficulties satisfactorily, however, and having observed the relative bearings of time, place, and means to the crime itself, the question of individuals is the important one to be determined. It often happens that there is no concealment of identity, the problem to be solved being simply the way to catch the guilty parties; but, on the other hand, the greatest skill, experience, patience, and perseverance are sometimes required to discover, first of all, the persons engaged in the crime. Indeed, an operation is often divisible into two distinct methods of action, the first being to find out the identity of the criminals, the second to follow up and capture them. In the course of a blind trail, such as we were obliged to travel in the case of this express robbery, it was impossible to know whence the men had come or whither they had gone; hence, I was forced to take up every trifling clue and follow it to the end. Even after I was satisfied in my own mind of the identity of the criminals, the agents and officers of the express company were continually finding mares' nests which they wished investigated, and the operation was sometimes greatly hindered on this account. As an example of the number of discouragements which the detective must always expect to encounter, I propose to mention some of the false scents which we were forced to follow during this operation. Three or four days after William's arrival in Union City, he was informed by the superintendent of the express company having charge of the operation, that there was a young man in Moscow who could give important information relative to the first robbery at that place. This young man, Thomas Carr by name, was a lawyer who had once had fine prospects, but he had become very dissipated, and he finally had been taken seriously ill, so that he had lost his practice. On recovering his health he had reformed his habits, but he had found great difficulty in winning back clients, and his income was hardly enough to support him. On learning that this impecunious lawyer had valuable information, William strongly suspected that it would amount to little more than a good lie, invented to obtain money from the express company; nevertheless, he sent for the young man and heard his story.