I really don't think he's dead.
This is the opening line of the novel. Marcus says this to Packy, Flossie, and Tipper. Jack says something at the end of the novel, when lies dying and tells Marcus, "I really don't think I'm dead." The line is not to be taken literally. It means that Jack lives because he has a hold on the American imagination. The legend of Legs Diamond survives the death of the man. Marcus uses this statement as a touchstone for seeking out all of the many ways Jack Diamond lived, both before and after his death. Even during Jack's lifetime, it was obvious that the myth of Jack "Legs" Diamond had a life of its own, a myth that was built up and cut down by the press and by word of mouth. After Jack's death, the stage shows of Kiki and Alice kept his reputation fresh. And four and a half decades later, with the creation of Legs, Jack lives in the pages of this novel.