On December 16, 1944, Hitler's last great offensive of World War II commenced, pushing through the Ardennes in an attempt to reach the Meuse River and, beyond it, the Allies' supply ports. Equipped with Tiger tanks, Kampfgruppe Peiper, Germany's most powerful battle group, spearheaded the offensive but failed to reach the Meuse. Using a wide variety of sources, the authors tell the story of Kampfgruppe Peiper in unprecedented detail, from the first day of the invasion through the group's retreat on Christmas Day.