He went even farther than that, moreover, interceding with a local judge for the medical students, with the result that their transgression was never made public, and the Dabney Medical College escaped without a smirch on its reputation. So the strange case ended to the satisfaction of all--save the knaves responsible for it. THE END. “The Mark of Cain; or, Nick Carter’s Air-line Case,” will be the title of the long, complete story which you will find in the next issue, No. 148, of the NICK CARTER STORIES, out July 10th. You will also find several other articles of interest, together with the usual installment of the serial now running. Sheridan of the U. S. Mail. By RALPH BOSTON. CHAPTER I. THE BOSS DEFIED. The man in the gray uniform of Uncle Sam’s postal service laughed lightly. “Don’t talk like a boob,” he said. “I’m not defying any organization, and I have no desire to make an enemy of Mr. Samuel J. Coggswell or anybody else. If he’s petty and narrow-minded enough to get sore on me just because I refuse to give up five dollars for a picnic ticket for which I have no earthly use, well, I can’t help it.” The smile upon his good-humored face suddenly gave place to a sterner expression. “And let me tell you,” he went on, “I don’t like your method of selling tickets. The way you go about it looks to me very much like blackmail. I never had the pleasure of meeting your friend, Mr. Coggswell, but if he instructed you to hold up strangers on the street, and hand them that line of talk, I haven’t any use for him; and you can tell him I said so.” The stout, red-faced, flashily dressed young man who had accosted the letter carrier on the street corner just as the latter was about to enter Branch Post Office X Y, scowled at this utterance. “Oh, I’ll tell him, all right,” he retorted. “You can bet he’s goin’ to hear about your freshness. What’s your name, anyway?” “Owen Sheridan,” was the prompt reply. The other produced a pencil and memorandum book from his vest pocket and ostentatiously made a note of the name. “Very well, Mr. Sheridan,” he sneered, “we’ll see how you’ll feel when you’re on Boss Coggswell’s black list. Guess he’ll make you lose that cocky air before long.” He turned on his heel and sauntered off up the street. Carrier Sheridan, who had just returned from his delivery route, entered the post office and went upstairs to the “swing room”--the place in which the carriers lounge between tours--and joined a dozen of his gray-coated comrades who were indulging in a few minutes of idle chatter.