An oil rig in Japan is completely destroyed, leaving almost no survivors. A plane is ripped from the sky, lost to the darkest depths of the sea. A group of rebel scientists team up to discover the cause: a prehistoric megalodon shark and a giant octopus have been unleashed thanks to an illegal military operation involving a 5-mile stretch of glacier falling into the ocean. The government, desperate to stop the creatures, learns of the scientists’ findings, and forces them to devise a plan to destroy the two horrific prehistoric sea creatures. The scientists do not want to obliterate these beasts, because they are “the biggest discovery of our time.” The first attempt to trap the shark and octopus goes horribly wrong, proving these monsters will not easily fade back into the history books. Now, the scientists have no choice but to destroy the beasts once and for all, and must do so without annihilating the rest of the world in the process.