The opening instalment reveals how the PoWs set about building three huge tunnels and preparing 200 men for escape from Stalag Luft III.

In the second episode, Roger Bushell and the X Committee are devastated when their tunnel, nicknamed Tom, is discovered and destroyed by the Nazis. Later, the PoWs face a multitude of problems as they finally make their escape.

As they take their opportunity to flee, 76 out of the 200 prisoners manage to escape, and must navigate hostile enemy territory to evade being recaptured when an unrelenting Nazi manhunt ensues. Eventually, 73 of the prisoners are caught, and Hitler orders more than half of those captured to be murdered by the Gestapo. For the three prisoners who evaded capture, the escape turns into a battle of their own as they cross Europe to safety in Allied territory.