It is 1941 and the Royal Navy are hard pressed to hold the enemy at bay. The Nazi army dominates Europe and in the North Atlantic U-boats strike at will. From the North Sea, down through the English Channel and into the Bay of Biscay, the battle for naval supremacy is hard fought. For Lieutenant-Commander Richard Thorburn, Captain to the small destroyer Brackendale, the war has become a series of rapid deployments. Again summoned at short notice, Thorburn finds himself thrust into a battle where his duty, courage and compassion will be tested to the full.