NOVA excavates the site of World War II's most daring prison break to learn how Allied POWs pulled it off.

The movie The Great Escape, starring Steve McQueen, was based on fact - the most daring and technically ingenious prison escape of World War II. The location was a remote high-security internment camp, for Allied airmen, known as Stalag Luft III, at Sagan in present-day Poland. It was a stunningly ambitious plan: Allied POWs set out to dig three tunnels, each over 300 feet long and 30 feet below ground - nicknamed "Tom,""Dick"and "Harry"- so that if the Germans discovered one tunnel there would be a fallback. NOVA follows a team of archaeologists on a hunt for the single surviving tunnel, "Dick,"which the Germans never found. Accompanying the team was a group of three of the original escapees, returning to the scene of their daring escapade for the first time in 60 years. The program presents the ingenious methods and devices improvised by the prisoners: how they surveyed the tunnels, disguised the entrance traps and engineered an amazing air pump and railway system, all from materials scavenged from the camp. But when the time for the breakout came, the thrill of the escape would take an unexpected and tragic turn.