The best known and most notorious PoW camp in history is Colditz, an 18th century castle in eastern Germany. With its imposing walls, steep cliffs, and rigorous policing, it was seen as the ultimate prison, home to the worst troublemakers from allied PoW camps all over Europe. Using archive material and dramatic reconstruction, and the personal testimony of Colditz veterans, this series documents the creative and often spectacular attempts to go over, under, around or through the walls. A specially commissioned archaeologist, working with the veterans, also uncovers the secret rooms, hidden tunnels and concealed doors that were so important in securing each precious escape from Colditz. At the start of 1942, British prisoners were lagging behind the French and Dutch in terms of "home runs" but the British success rate was about to improve, as they were getting help from a new source.