Volume 3 (a four-volume series) about the German submarine base in Lorient, France, tells the history of the 92 German submarines that were stationed there between August 1942 and August 1943 or arrived at the port. On 1 October 1942, some Type IX submarines left the port of Lorient in the direction of Cape of Good Hope to hunt allied ships there. The book also describes the devastating effects of the Allied bombardment on the city and port of Lorient during the following months and examines the progress in the defenses against the German submarine weapon, which led to the withdrawal of the German submarines from the North Atlantic towards the end of May 1943.

The volume is illustrated with over 500 rare contemporary photographs as well as maps and plans.

A final chapter shows in color important locations, architectural remains that have survived the time, documents and memorabilia related to the presence of the submarines in Lorient.