In September 1942, a U.S. Army Air Force pilot, Lieutenant Grant, crash-lands his photo reconnaissance plane in Swiss territory after catching a glimpse of a previously unknown Nazi secret weapon, a jet aircraft. The Swiss authorities imprison Grant, along with his navigator. Grant escapes and is soon enmeshed in a complicated plot that centers on Swiss collaboration, a Russian commander fresh from the Battle of Stalingrad, the Russian's ex-wife and secret negotiations that may result in a truce between Germany and Russia thus freeing Hitler's forces from fighting the war on two fronts.