After escaping an attack by what he claims was a 70-foot shark, Jonas Taylor must confront his fears to save those trapped in a sunken submersible.

A deep-sea submersible filled with an international research crew lies disabled at the bottom of the Pacific after having been attacked by a massive shark previously thought to be extinct. With time running out, expert deep sea rescue diver Jonas Taylor is recruited by a visionary Chinese oceanographer to save the crew and the ocean itself from this unstoppable threat that is a pre-historic 75-foot-long shark known as the Megalodon.