In December of 1944, the Allied high command is convinced that German forces in Belgium are in a low state of readiness, and perhaps even about to withdraw. Only one officer on the front lines, intelligence specialist Lt. Col. Kiley (Henry Fonda), believes otherwise -- that the Germans are actually planning an attack. His opinion is rejected by his immediate superior (Dana Andrews) and his commanding general (Robert Ryan). Kiley spots several suspicious signs of German activity behind enemy lines on a reconnaissance flight, and he is at the front looking for evidence when the German counter-offensive starts. Taking advantage of Allied unpreparedness and a weather front that grounds all aircraft, their heavy tank units, supported by infantry, roll over the American forces, assaulting the lines at five different points in an attempt to ultimately divide the Allied forces in the west. The German top tank officer, Colonel Hessler (Robert Shaw), has planned his operation perfectly, but he is in a race against time, to take as much territory as possible before the weather front moves out and American aircraft can fly again, and to capture the American fuel supplies so that the offensive can continue right to the port of Antwerp. He has the total dedication of his men, but engenders doubts from his aide, Conrad (Hans-Christian Blech), who is weary of the fighting and wonders what it is all for. Meanwhile, Kiley is trying to uncover the weak spot in the German offensive, and he crosses paths with several other key players in this drama: Charles Bronson as a combat officer charged with the defense of the collapsing American position, James MacArthur as a neophyte lieutenant who becomes a leader, and Telly Savalas as a conniving sergeant in command of a tank who unexpectedly finds a nobler, less mercenary side of himself.