It's a journey across the globe, and back in time, as Danny must familiarize himself with diesel-powered submarines and the heroic World War II captains who commanded them.

    The author witnessed the mud-soaked agony of the Battle of Passchendaele in 1917, and the rapidly moving events of the following year. The book contains one of the most extraordinary accounts of the German spring offensive in 1918, from the point of view of a gunner officer with a grandstand view of the ruthless German advance.The author's father was Prime Minister at the outbreak of the first world war. The author's three brothers also served during the war; his eldest brother died during the Battle of the Somme.