For Humphrey Bogart's son, making sense of and peace with the father he lost at an early age has led him down a path of understanding that he now reveals. Along the way, he came up with surprising anecdotes involving Frank Sinatra, Bette Davis, John Houston, Audrey Hepburn, and Stephen Bogart's stepfather, Jason Robards, that make the real Humphrey Bogart come vividly to life. photos.