It is February 1943 and as the balance of the war slowly changes in Britain's favour, Lieutenant Commander Steven Marshall brings his battle-scarred submarine into home port. But if the enemy collapse is to be exploited, Marshall and his men must soon return to the Mediterranean.

It is February 1943 and as the balance of the war slowly changes in Britain's favour, Lieutenant Commander Steven Marshall brings his battle-scarred submarine into home port. But if the enemy collapse is to be exploited, Marshall and his men must soon return to the Mediterranean.