A deep-sea submarine, part of an international program, is attacked by a huge creature and is damaged at the bottom of the deepest ocean floor in the Pacific, with its crew trapped inside. Time is running out and a Chinese oceanographer, Dr. Chang, recruits Jonas Taylor (Jason Statham), a specialist in deep water rescue, against the wishes of his daughter Suyin (Li Bingbing) who believes he can rescue the crew by their own means. But both must join forces to save the crew and also the ocean of an unstoppable threat: a 23-meter prehistoric shark known by the name of Megalodon. Although it was believed to be extinct, the Meg is alive and kicking … and is hunting. Five years before, Jonas had encountered this same frightening creature, but nobody believed him at that moment. Now Jonas must face his fears to return to the deep sea … where he will come face to face with the most fearsome predator of all time.