Barca - a mere snag on the North African coastline. But for veteran U-boatman Baldur Wolz, alias Sea Wolf, the tiny British submarine base was to become synonymous with all the horror, sweating suspense and gruelling tension of undersea combat.

Wolz had been hand-picked to pioneer the Hecht, the latest addition to Kriegsmarine's deadly underwater weaponry. But, as he guided his lethal steel shark in for the kill, he had no inkling of the devastating trap that had been laid for him - a trap whose savage jaws were about to snap shut...