On a remote former submarine refueling facility called Aquatica, a team of scientists are searching for a cure for Alzheimer's disease. Dr. Susan McAlester (Saffron Burrows) genetically engineers three Mako sharks, intending to increase their brain capacity so that they can harvest the tissue as a cure for Alzheimer's. Unfortunately, the increased brain capacity also makes the sharks smarter, faster, and more dangerous. Aquatica's financial backers are skeptical and nervous about the tests, and send a corporate executive (Samuel L. Jackson) to visit the facility.