This book tells the saga of a German front-line U-Boat, U-175, which, with her compatriots, very nearly severed Britain's lifeline across the Atlantic, and which culminated in a critical battle around Convoy HX-233 in the Spring of 1943. The author was a witness to the battle and this, combined with the meticulous research of original documents and his use of eye witness accounts from both the Allied and German sides, has resulted in a quite remarkable piece of work in which no stone has been left unturned in his desire to reconstruct exactly what happened both to the U-boats and their quarry in the crucial months of 1943. But the book is much more than a description of a single battle, for the author takes this particular event as a microcosm to explain the strategic and tactical background, the technical developments on both sides, and the operational experiences that occurred thoughout the whole of the War.