Deep Blue Sea is a 1999 science fiction horror film directed by Renny Harlin and written by Duncan Kennedy, Donna Powers, and Wayne Powers. It stars Thomas Jane, Saffron Burrows, Samuel L. Jackson, Michael Rapaport and LL Cool J. The film follows a team of scientists in an isolated underwater facility who are researching the brains of mako sharks to help fight Alzheimer's, only for the sharks to go on a rampage after two of the scientists, Susan McCallister and Jim Whitlock, genetically enhance their intelligence in secret.