Sławomir Dębski’s book presents a brilliant reconstruction of the sequence of events from the point at which Germany clinched its rapprochement with the Soviet Union in August 1939 until the open clash of the two totalitarian Powers in June 1941. His book answers key questions about the motives that prompted Hitler and Stalin to reach a deal and the reasons why their alliance collapsed. Dębski offers his readers a set of novel and thoroughly thought-out assessments, with an original account of diplomatic relations between the Third Reich and the Soviet Union in 1939-1941, based on his examination of German, Soviet, and Polish sources. The study is