Eleven days into their marriage, Alabama couple Gabe Watson and his wife Tina Watson go scuba diving near Australia's Great Barrier Reef, where Tina drowns in what appears to be a freak accident. But her father Tommy Thomas begins to suspect that his daughter's death was by no means an accident, a belief shared by authorities in both United States and Australia, including Detective Gary Campbell. An investigation ensues, as does a media frenzy and a series of legal battles.