At a remote underwater research facility, a team of scientists, led by Dr. Susan McAlester, is working on a potential cure for Alzheimer's disease. To achieve this, they have genetically engineered mako sharks to increase their brain size, allowing for the extraction of a protein complex that holds promise for their research. However, these genetic modifications enhance the sharks' intelligence and make them more dangerous. Tensions rise as the corporate sponsor, Russell Franklin, visits the facility to evaluate progress just before a scheduled extraction procedure. During the experiment, one of the sharks seemingly responds with calculated aggression, initiating a chain of increasingly perilous events.

The sharks, now possessing heightened cognitive abilities, undertake a series of strategic attacks that compromise the facility's structural integrity, leading to flooding and isolating the research crew. As the team fights for survival, they must navigate the flooded interiors and outsmart the predatory sharks that have turned their research against them. Faced with dwindling resources and growing casualties, the survivors are forced into a desperate struggle, relying on their wits and teamwork to find a way out of the underwater deathtrap before it becomes their final resting place.