Why had the stranger come back to the old neighborhood after twenty years?

The stranger—"Silky" Bob—has returned to the neighborhood after all these years because of a promise he and his old friend Jimmy Wells once made to each other. Jimmy and Bob had grown up together in New York, but Bob decided to head out West to seek his fortune. On the night before Bob left, he and Jimmy vowed to each other they would meet up again in twenty years time on that exact day outside "Big Joe" Brady's restaurant in New York City. This was the place where the two close friends dined the night before Bob left New York. Bob would choose to make his fortune as a master-criminal. But unfortunately for him, his old pal Jimmy would opt for a career in law enforcement.