'Attack and Sink' was the signal that Admiral Donitz sent to the commanders of the 21 U-boats of the Markgraf wolf-pack on the 9th September 1941. Convoy SC42 consisted of sixty three merchant ships, many of them British, many old and dilapidated and all slow and heavy-laden with vital supplies for the United Kingdom, was strung out in 12 columns abreast, covering an area of 25 miles of inhospitable ocean. They set sail from 'Nova Scotia' at a time when the German U-boats were sinking more than one hundred ships a month. Their escort of one destroyer and three corvettes of the Royal Canadian Navy, all untried in combat, were hopelessly outclassed when the battle of SC42 commenced when it was in sight of the coast of Greenland. The battle lasted for seven days and covered 1,200 miles of ocean.Captain Bernard Edwards has written another superb story of courage and endurance and has dedicated this book to all those who fought and died in the battle of convoy SC42. First hand accounts of the participants on both sides add to the interest and drama.