Upper class twit Wing Commander Forrester (Stephen Fry) is imprisoned in Stalag Luft, a German World War 2 POW camp. He devises a plan with Cosgrove (Nicholas Lyndhurst) for a mass escape and digging begins on five tunnels, Tom, Dick, Harry, Julian and Gladys. Assuming the name 'Big F' Forrester believes his plan will succeed because his German captors are old and incompetent. Realising the vulnerability of his position, Camp Kommandant (Geoffrey Palmer), requests that his officers are allowed to join the escape. Once the Germans have escaped through the tunnel the allies get cold feet and decide to remain in the POW camp and run it themselves. The only problem being that there are now no Germans so Forrester assumes the role of Camp Kommandant and enlists the help of some German speaking POWs, but will they convince the visiting SS guards?