'Once Upon a Time in Tombstone' delivers all of the great characters you would expect in a film about Tombstone — The Earp Brothers, The Clanton Brothers, Doc Holliday, Johnny Ringo, etc. — and of course, great gunfights. What the film delivers that other films about Tombstone did not is a multitude of pieces of the puzzle that complete the story, not just about why the gunfight happened but the real history about what led up to it and what followed.