A surprise attack on a U.S. Naval sub leaves Commander Frank Habley in a trail of destruction. Held responsible for the attack, Habley must deal with being relieved of his naval command as well as suffer in silence over the loss of his longtime partner, Tom. But when the enemy's stealth sub begins to strike again, Habley is reinstated and must contend not only with a mysterious aggressor, but also the vengeful sister of his lover and a Lieutenant who has his own agenda.