Virgil 'Bud' Brigman (Ed Harris) is the lead foreman of Deepcore, an underwater oil drilling rig 2,000-feet deep. Deepcore receives word of a downed US Navy nuclear submarine in the area near the Cayman Trough. As Russian subs are close by, foul play is suspected. The crew must escort Bud's soon-to-be ex-wife Lindsay (Mary Elizabeth Mastrantonio), the project engineer for Deepcore, and a crew of Navy SEALs for a rescue mission.  A hurricane cuts communication outside, effectively leaving Navy SEAL Lieutenant Coffey (Michael Biehn) in command. Psychosis from pressurization makes Coffey unstable and paranoid, viewing the various neon-colored NTIs (Non-Terrestrial Intelligence) in a nearby abyss as enemy Russian vessels that must be destroyed. James Cameron writes and directs.