Billy Byrne squared his broad shoulders and filled his deep lungs with the familiar medium which is known as air in Chicago. He was standing upon the platform of a New York Central train that was pulling into the La Salle Street Station, and though the young man was far from happy something in the nature of content pervaded his being, for he was coming home. After something more than a year of world wandering and strange adventure Billy Byrne was coming back to the great West Side and Grand Avenue. Now there is not much upon either side or down the center of long and tortuous Grand Avenue to arouse enthusiasm, nor was Billy particularly enthusiastic about that more or less squalid thoroughfare. The thing that exalted Billy was the idea that he was coming back to _show them_. He had left under a cloud and with a reputation for genuine toughness and rowdyism that has seen few parallels even in the ungentle district of his birth and upbringing. A girl had changed him. She was as far removed from Billy's sphere as the stars themselves; but Billy had loved her and learned from her, and in trying to become more as he knew the men of her class were he had sloughed off much of the uncouthness that had always been a part of him, and all of the rowdyism. Billy Byrne was no longer the mucker.