"I will," Lawrence returned seriously, "if they get on to the case. What is it?" "Donovan—James F. Donovan." Barry noted it on a bit of paper with the inward determination to reward the boy in some way; then, after another word of thanks and a quick handshake, he sprang to his feet and made his way hastily to the door. Three minutes later he was interviewing the telephone girl at the Merton House concerning the tall, slim man with the top hat who had called a certain number earlier in the evening. The young woman remembered the incident perfectly, and was able to add one or two particulars which had escaped the messenger boy, but which only made certain Barry’s impression that he had never set eyes on the unknown. On his way out he scrutinized the hotel stationery, but without any real hope that it would prove identical with that on which the letter, was written. In the doorway he paused undecided. The fact that the man had sent his message from the Merton House showed absolutely nothing. He might have come from a totally different part of town in order to divert suspicion and throw possible pursuers off the track. That would be a natural move, anyway, and Lawrence hesitated a long time before an idea came to him. Then suddenly his eyes brightened and he glanced swiftly up Fourth Avenue. He knew the neighborhood very well, and could recall no stationery shop near it. Nevertheless, he told the chauffeur to drive slowly around the square, and to stop if he rapped on the glass. The circuit was of no avail. The taxi reached the southwest corner without the signal having been made, and Barry told the man to proceed on down University Place at the same slow speed. A block passed, then another; but before the third corner had been reached Lawrence struck the glass with such force as nearly to shatter it, and, leaping out of the still-moving machine, darted into a narrow little shop bearing a sign above the door to the effect that stationery and cigars could be had within. As the girl came forward, he fumbled in his pocket and produced the letter. "Have you any writing paper like this?" he asked, extending it to her, but still retaining a hold upon one corner. She bent forward to glance at the texture, and at that instant Barry realized with a start that he had handed her the letter which had come from the little man in black, inclosing the five one-hundred-dollar bills. "I beg pardon," he said hastily. "I’ve made a mistake. This is the kind I want." He drew forth the other letter; then, with a swift catching of the breath, stood staring stupidly from one to the other. For a second he did not move. He could not believe this odd coincidence. He held the two sheets to the light. The watermarks were identical. He lowered the sheets and examined them intently. In size, color, texture, quality they could not have been more alike had they come from the same box. What did it mean? *CHAPTER XXXVIII.*