It's hard to say what's the most harrowing moment: Sheen's psychic meltdown, Brando's mumbling miscues and diva-like behavior, or Coppola's certainty that he's making a terrible movie. Certainly things get off to a poor start when Sheen suffers a heart attack, but the real-life catharsis that may have triggered it it winds up in a key early scene. The chaos of the shoot even perturbs the usually unflappable Dennis Hopper. Watching "Hearts," you wonder how the critically acclaimed "Apocalypse"— helmed by a neurotic director, with everything on the line, who couldn't seem to catch a break — ever made it to the screen. Don't miss this tense, unforgettable chronicle of one filmmaker's often agonizing journey to greatness.