A team of underwater researchers and military personnel is stationed at a deep-sea naval facility miles below the ocean’s surface. Their mission is to install a nuclear missile storage platform on the sea floor, but as they carry out their work, they discover an enormous underwater cavern. A debate ensues about whether to explore this uncharted territory. Ignoring some of the crew's concerns, the leaders of the mission decide to proceed, prepared for potential risks. However, their exploration disturbs an ancient and deadly creature that has been dwelling in the hidden depths.

The situation rapidly escalates as the monstrous entity begins attacking the facility and its inhabitants, causing catastrophic damage and turning their mission into a struggle for survival. The crew must now desperately work together, battling both the relentless creature and their own mounting fear, to find a way to escape the underwater installation before it is completely destroyed. Amidst the ensuing chaos, personal conflicts flare up, and loyalty is tested, raising the stakes for everyone involved. As resources dwindle and time runs out, the group faces seemingly insurmountable odds in their quest to outsmart the formidable predator and reach safety.