Nick adjusted it carefully, then held the back of the envelope in the thread of steam until the heat and moisture softened the paste on the flap, which he then opened without injury, removing the letter and laying the envelope aside to dry. “Now, Chick, we’ll see what Martin has to say in this special delivery,” he remarked complacently, while unfolding the single sheet of paper so artfully taken from its cover. Chick drew nearer to gaze at it. The communication also was typewritten, on a sheet of perfectly plain paper. It read as follows: “Dear Gus: The pay-roll package goes through to-night, Tuesday, on the Southern Limited. We’ll have the substitute down fine in ample time, and the other dead to rights. Be on hand to relieve us of the goods at the point agreed upon. Nothing doing until south of North Dayton. It looks like a walk-over. I will see you after turning the trick. Martin.” Nick Carter glanced through the letter, then read it aloud to his two companions. The significance of it could not be mistaken. “By gracious!” Holden exclaimed. “You were right, Mr. Carter. It’s a job to rob the express car on the Southern Limited.” “Nothing less,” said Nick. “I suspected something of the kind.” “That train is due here from Philadelphia soon after midnight.” “A fit hour for such a felonious job,” Nick declared. “But we must be equal to the needs of the hour. Not a word of this to others, Holden, under any circumstances.” “Surely not. You can depend upon my discretion.” “I will make a copy of this letter. You then may reseal it and have it delivered precisely as if it had not been opened.” “I will do so, Mr. Carter.” It took Nick only a few moments to make the copy. Holden had not finished resealing the letter, however, when the ringing of the telephone was the harbinger of a communication from Patsy. “Hold that letter until after I have a talk with him,” Nick directed. Patsy’s report was brief and to the point. “John Dalton is not known here,” said he, speaking from a booth in the Reddy House. “Gus Dewitt arrived here two days ago. He has been here on other occasions for a day or two, but nothing definite is known about him. He now is in the hotel office and evidently is waiting for the special-delivery letter.” “Anything more?” Nick inquired. “That’s all to date,” returned Patsy. “I’ve got my eye on the man.” “Keep it on him, Patsy, after he receives the letter,” Nick directed. “Shadow him, if possible, or find some way to trail him. Listen while I tell you what the letter contains. It may be of advantage to you.” “Shoot! I’m all ears,” said Patsy. Nick then repeated the letter verbatim and told Patsy of what his suspicions consisted, again directing him to make a special mark of Dewitt until otherwise instructed. Replacing the receiver, Nick then turned to the postmaster and said: