Mines are impartial killers and present a lethal challenge to volunteers in the Special Countermeasures of the Royal Navy. These brave, lonely men either have something to prove, or nothing left to lose. Meet Lieutenant-Commander, David Masters -- haunted unrelentingly by a split second glimpse of the mine that destroyed his first and only command, H M Submarine, Tornado. He now defuses the treacherous 'beast' on land, and teaches the same deadly science to others who too often die in the attempt. Lieutenant Chris Foley, mine-laying off an enemy coast in ML366, rolls on an uneasy sea with a release bracket sheared and a lie-mine jammed, listening to the menacing growl of approaching E-boats. And Sub-Lieutenant, Michael Lincoln, who's been hailed as a hero, dreads being exposed as a coward even more than he dreads the unexpected booby-trap, or the gentle whirr of the activated fuse -- marking the last twelve seconds of his life.