By the spring of 1944, hundreds of American heavy bombers were venturing deep into occupied Europe, escorted by ever increasing numbers of Mustangs, Thunderbolts and Lightnings. In a desperate attempt to deal a single knock-out blow to the Allied daylight bomber offensive, an outstanding band of Luftwaffe fighter pilots volunteered to be organised into elite bomber destroyer units known as Sturmgruppen, or ‘assault wings’. Pilots in these units were trained to engage the enemy in close-quarter combat. Through first-hand accounts and rare archival photography, this book chronicles the brief but violent career of the Sturmgruppen during the dark days of 1944.