The principal object in the room was an old-fashioned flat-topped desk so placed between the windows that the light would fall over the user's shoulders. The desk was covered with papers, and the merest glance was enough to show Jack that he had here the conclusive evidence that he had been so long in search of. He decided to call in official help now. There was a telephone on the desk, but he hesitated trusting his secret to it. Instead, he wrote a note to the Deputy Commissioner, asking for two plain clothes men to be sent him at once. This he entrusted to Tommy, instructing him to take a taxicab to police headquarters. The door was fitted with a spring lock of the usual pattern. It had not been injured, and when the door closed it locked itself. As soon as he was left alone Jack set about making a careful examination of the place. He figured that should the owner return, the sound of the key in the lock would give him sufficient warning. He laid his automatic ready to his hand on the desk. He was careful to make no sound that would warn any one who might stop to listen at the door before entering. First he took a general survey. The two windows of the room looked out on an array of back yards and on the rear of a long row of similar buildings in the next street. One of the windows opened on a fire escape. At one's right as one faced the windows was an old-fashioned fireplace: across the room were two doors, the lower giving on the stair hall, the upper presumably on the hall room adjoining. The latter door was screwed to its frame. At the other end of the room from the windows was a large closet. Jack, fearful of being trapped by the return of the owner merely looked in here. It was set out with a bureau and mirror, and from pegs around the walls depended an extraordinary assortment of clothes. Jack saw that there was a complete separate outfit on each peg; fine clothes and mean, native and foreign; a policeman's uniform, and a complete turn-out for a woman. Above the pegs a shelf ran around, and over each peg was a box which presumably contained the smaller articles to complete each make-up. Interesting as was this exhibit, the papers in connection with the desk quickly drew Jack away from it. Behind the desk there was an object which whetted his curiosity to the highest degree. This was an oaken cabinet with drawers of the kind that are used to contain modern card index systems. Jack eagerly pulled out the top drawer. Inside was a set of large cards, each headed by a name in the usual manner, and with various particulars as to that individual entered beneath. As the scheme became clear to him Jack's heart beat fast. He could scarcely credit the evidence of his senses. It appeared that he held in his hands a complete record of the operations of "Mr. B." What strange freak of vanity could have led the criminal to collect such a mass of damning evidence! Here was one card chosen at random.