1. Prologue: The film begins with a present-day expedition to the wreck of the Titanic, led by treasure hunter Brock Lovett. Rose DeWitt Bukater, a 100-year-old woman, is brought aboard the research vessel and reveals that she was a survivor of the Titanic's sinking.
2. Part I: Embarkation: The film then flashes back to 1912, as Rose boards the Titanic with her wealthy fiancé, Caledon Hockley. Rose's mother, Ruth, is also traveling with them. They sail from Southampton, England, on the ship's maiden voyage.
3. Part II: The Sinking: The film depicts the events of the night of April 14-15, 1912, when the Titanic strikes an iceberg and sinks in the North Atlantic Ocean. Rose and Jack Dawson, a third-class passenger whom she meets on the ship, become romantically involved as the ship sinks.
4. Part III: Aftermath: The film ends with Rose recounting her experiences on the Titanic to Lovett and his crew. She reveals that she kept the Heart of the Ocean necklace, a valuable diamond that was stolen from Caledon, and throws it into the ocean. The film ends with Rose dying peacefully in her sleep.