The submarine U.S.S. Manta had a perfect record until the mysterious death of its captain. The next in command, Lt. Richard Brice, is determined to steer his disheartened crew back to safety. But after three battle survivors board the sub, bizarre and frightening things start to happen. As the eerie tale unfolds, and crew members begin to disappear, Ensign Douglas O'Dell must piece together the puzzles of the submarine's past before it is too late to resurface alive.