Deep Blue Sea is a 1999 American science fiction horror film directed by Renny Harlin. It stars Saffron Burrows, Thomas Jane, Samuel L. Jackson, Michael Rapaport, and rapper LL Cool J. Set in an isolated underwater facility, the film follows a team of scientists and their research on mako sharks to help fight Alzheimer's disease. The situation plunges into chaos when multiple genetically engineered sharks go on a rampage and flood the facility.
In an underwater facility, a team of scientists is doing research on mako sharks to help in the re-activation of dormant human brain cells like those found in Alzheimer's disease patients. After one of the sharks escapes the facility and attempts to attack a boat full of young adults, financial backers send corporate executive Russell Franklin to investigate the facility. In the laboratory, doctors Susan McAlester and Jim Whitlock prove their research is working by testing a certain protein complex that was removed from the brain tissue of their largest shark.