In an alternate world where the mere presence of American superheroes changed history, the US won the Vietnam War, Nixon is still president, and the Cold War is in full effect. 'Watchmen' begins as a murder-mystery, but soon unfolds into a planet-altering conspiracy. As the resolution comes to a head, the unlikely group of reunited heroes - Rorschach, Nite Owl, Silk Spectre, Dr Manhattan, and Ozymandias - have to test the limits of their convictions and ask themselves where the true line is between good and evil.