Following the greatest failure of Allied intelligence since Pearl Harbor, on the morning of December 16, 1944, a huge German army of 600,000 men smashed into the American troops who were holding the line in the snowbound hills of the Belgian Ardennes. A handful of German special forces, wearing U.S. uniforms, driving U.S. equipment, and operating behind the U.S. lines, caused chaos and havoc. Among their number was the legendary Otto Skorzeny, who had previously achieved notoriety when he masterminded and executed the daring rescue of Mussolini from his mountain haunt. These German specialists, working right under the noses of Allied intelligence, nearly turned a German defeat into victory at a time when the Allied top brass were predicting the war would be over by Christmas.