In 1912, a young, wealthy woman named Rose boards the RMS Titanic, destined for New York City from Southampton with her fiancé Cal and her oppressive upper-class family. Trapped in a life of suffocating etiquette and expectations, she feels despair at the path her life is taking. Meanwhile, a spirited, penniless artist named Jack wins a third-class ticket for the Titanic in a poker game and boards the ship full of hope and dreams of a better life in America. Their worlds collide when Jack sees Rose contemplating a drastic escape from her life and intervenes, forging an immediate connection between them.

As the ship sails toward its fate, the two develop a clandestine romance that blooms despite the stark class divisions on the ship. Their relationship challenges the rigid social norms and allows Rose to rediscover her zest for life, encouraging her to pursue her own desires and freedoms. However, their newfound love is threatened not just by Cal's jealousy and the disapproval of Rose's family, but also by the inevitable disaster looming over the Titanic. As they navigate their feelings for each other among the opulence and grandeur of the ship, the passengers remain blissfully unaware of the tragedy that awaits them in the cold waters of the North Atlantic.