Col. Nicholson (Alec Guiness), determined to get the battallion back togather, agrees to build the railway bridge for Colonel Saito, The POW camp commander, and manages to do so. Meanwhile, Cmdr. Shears, one of the POW, manages to escape the camp and get to Ceylon where Allied forces are, but is then recruited for a daring sabotage mission to destroy the bridge. He sets off with his commander and a young, hasitant soldier. Once they arrive, they put expolsive on the bridge's suuporters, and wait untill morning, when the ammunation train will pass on the bridge. However, In the morning, Col. Nicholson discovers the explosives and, with Colonel Saito, follows the wires untill Saito is stabbed by the young soldier, who was hiding nearby. While in a safe place, the Soldier tells Nicholson that they are about to destroy the bridge. But as Nicholson hears the news, he screams in agony and calls for help. When the Japanese Soldiers arrive, a battle ensues between the commando team and the Japenes, in which Shears and the young soldier are killed. Nicholson, Realising his dreadfull mistake, whispers, "What have I done?!" before a mortar shot by the commando's commander hits the ground near him, thus killing him. As he falls, he lands on the detonator and the bridge explodes just as the train passes by. The POW medic, horrified by the sight he just saw, arrives at the battle scene and says, "MADNESS...! MADNESS...!"