Colditz Castle, a notorious prisoner of war camp in Nazi Germany, was supposed to be escape-proof. But in World War II, a group of British officers dreamt up an escape plan: in a secret attic workshop, they constructed a two-man glider out of bed sheets and floorboards. The plan was to fly to freedom from the roof of the castle, but the war ended before they could put it to the test. Now a team of aero engineers and carpenters rebuilds the glider in the same attic using the same materials and use a bathtub full of concrete to catapult the glider off the roof to find out if the legendary glider plan would have succeeded.