Tarzan and Jane Porter face a mercenary army dispatched by the evil CEO of Greystoke Energies, a man who took over the company from Tarzan's parents, after they died in a plane crash.

After a surfer dies off Morro Bay, Calif., on Christmas Eve, shark attack investigators Ralph Collier and Brandon McMillan use forensic evidence and eyewitness accounts to identify the suspected killer: an 18-foot great white.