Jackson "Jax" Slate, famous treasure hunter, is out to find the legendary ‘Lost Gold of Cortez’ in the open waters off a secluded island in the Caribbean Sea. Using dynamite to blast his way through centuries of silt, new chasms are created reaching miles below the ancient ocean floor. From here, an ancient evil is released, that quickly, savagely, and without warning, destroys Jackson’s boat and kills his crew. The sole survivor of the carnage, Jackson teams up with marine biologist, Sarah, to venture back to the site and investigate the horrific events. They extract an egg from the darkest depths of the ocean and take it back to the lab to investigate. But when it hatches, they realise they have awakened a deadly prehistoric monster, the P-Rex, which will stop at nothing until the entire island is destroyed.