On September 11, 1944, four American soldiers from the Fifth Armored Division crossed the river Our and entered Hitler's Third Reich -- the first hostile forces to penetrate German lines since the days of Napoleon. Above them on the heights they found abandoned bunkers of the vaunted Siegfried Line: a three-mile-deep series of fortifications with pillboxes, troop shelters, command posts, and antitank obstacles that ran along Germany's western frontier opposite the French Maginot Line. Four years earlier, British troops had boasted in song that they would hang their washing on the Siegfried Line, and now it seemed as if the Americans would fulfill that vow. But appearances proved as deceptive in 1944 as they had in 1940. By October, Allied troops were bogged down in one of the war's most bitter battles. Where the Siegfried Line ran through "the green hell" of the Huertgen Forest, three U.S. divisions were decimated. In December Hitler struck back, launching the Ardennes Offensive (also known as the Battle of the Bulge) from behind the Siegfried Line. Even after Generals Patton and Montgomery broke through in February 1945, two-thirds of the Siegfried Line still held firm in German hands. This masterful history recounts a crucial and compelling campaign in the twentieth-century epic that was World War II.