French nuclear tests irradiate an iguana into a giant monster that viciously attacks freighter ships in the Pacific Ocean. A team of experts, including Niko Tatopoulos, conclude that the oversized reptile is the culprit. Before long, the giant lizard is loose in Manhattan as the US military races to destroy the monster before it reproduces and it's spawn takes over the world.

101-year-old Rose DeWitt Bukater tells the story of her life aboard the Titanic, 84 years later. A young Rose boards the ship with her mother and fiancé. Meanwhile, Jack Dawson and Fabrizio De Rossi win third-class tickets aboard the ship. Rose tells the whole story from Titanic's departure through to its death—on its first and last voyage—on April 15, 1912.

Using massive piloted robots to combat the alien threat, earth's survivors take the fight to the invading alien force lurking in the depths of the Pacific Ocean. Nearly defenseless in the face of the relentless enemy, the forces of mankind have no choice but to turn to two unlikely heroes who now stand as earth's final hope against the mounting apocalypse.