Below, in the cold, dark waters off North Korea, the ultimate weapon of mass destruction has its sights on the U.S. fleet. Commander Burt Habley, who is operating a fast attack submarine, encounters the destructive, phantom sub that claims two of his crew. Court-martialed and suspended from further duty, Habley gets a second chance when a young, aspiring officer requests his involvement in a clandestine operation to tap an ocean communications cable. As soon as they enter the water, they become the hunted. When Habley attempts to dodge certain death by straying off course, his command is seized by the opportunistic Executive Officer and his Special Mission Ops. Now the deadly underwater game of cat and mouse will begin.