The German war machine is in retreat. Two American M 18 tank destroyers are sent to root out a die hard group of Nazis holed up in the Harz Mountains.The German war machine is in retreat. Two American M 18 tank destroyers are sent to root out a die hard group of Nazis holed up in the Harz Mountains.The German war machine is in retreat. Two American M 18 tank destroyers are sent to root out a die hard group of Nazis holed up in the Harz Mountains.