In 1996, aboard the research vessel Akademik Mstislav Keldysh, Brock Lovett and his team search the wreck of RMS Titanic. They recover a safe they hope contains a necklace with a large diamond known as the Heart of the Ocean. Instead, they find only a drawing of a young nude woman wearing the necklace. The sketch is dated April 14, 1912, the same day the Titanic struck the iceberg that caused it to sink.[Note 2] After viewing a television news story about the discovery, centenarian Rose Dawson Calvert contacts Lovett, identifying herself as the woman in the drawing. Hoping she can help locate the necklace, Lovett brings Rose aboard Keldysh, where she recounts her experiences as a Titanic passenger.
In 1912 Southampton, 17-year-old Rose DeWitt Bukater, her wealthy fiancé Caledon "Cal" Hockley and Rose's widowed mother Ruth board the Titanic. Ruth emphasizes that Rose's marriage to Cal will resolve the family's financial problems and maintain their upper-class status. Meanwhile, Jack Dawson, a poor young artist, wins a third-class Titanic ticket in a poker game. After setting sail, Rose, distraught over her loveless engagement, climbs over the stern railing, intending to commit suicide. Jack coaxes her back onto the deck and they develop a friendship. Jack soon admits that he has feelings for Rose. When Cal and Ruth object, Rose rejects Jack's attentions, but returns to him after realizing she has fallen in love.
Rose brings Jack to her state room and requests he draw her nude, wearing only the Heart of the Ocean. They later evade Cal's servant, Lovejoy, and have sex in a Renault Towncar inside the cargo hold. On the forward deck, they witness the ship's collision with an iceberg and overhear its officers discussing its seriousness. Cal discovers Jack's sketch and an insulting note from Rose in his safe, along with the necklace. When Jack and Rose return to warn the others about the collision, Cal has Lovejoy slip the necklace into Jack's pocket to frame him for theft. Jack is confined in the master-at-arms' office. Cal puts the necklace into his own overcoat pocket.
With the ship sinking, the crew prioritize women and children for evacuation. Rose finds and frees Jack, and they make it back to the deck, where Cal and Jack urge Rose to board a lifeboat. Intending to save himself, Cal lies that he will get Jack safely off the ship and wraps his overcoat around Rose. As her lifeboat is lowered, Rose, unable to abandon Jack, jumps back onto the ship. Cal grabs Lovejoy's pistol and chases Jack and Rose, but they escape. Cal realizes the necklace is still in the coat he gave Rose. He poses as a lost child's father to board a lifeboat.
Jack and Rose return to the deck. The ship's stern is rising as the flooded bow sinks; the two desperately cling to the stern rail. The upended ship breaks in half and the bow section sinks. The stern slams back onto the ocean, upends again and sinks. In the freezing water, Jack helps Rose onto a wood transom panel among the debris, buoyant enough only for one person, and makes her promise to survive. Jack dies of cold shock, but Rose is among six people saved by the one returning lifeboat. RMS Carpathia rescues the survivors. Rose avoids Cal and her mother by hiding among the steerage passengers and giving her name as Rose Dawson. Still wearing Cal's overcoat, she discovers the necklace tucked inside the pocket.
In the present, Rose says she heard that Cal committed suicide after losing his fortune in the 1929 Wall Street crash. Lovett abandons his search after hearing Rose's story. Alone on the stern of Keldysh, Rose takes the Heart of the Ocean, which has been in her possession all along, and drops it into the sea over the wreck site. While she is seemingly asleep in her bed,[17] her photos on the dresser depict a life of freedom and adventure inspired by Jack. A young Rose reunites with Jack at the Titanic's Grand Staircase, applauded by those who died that night.
