In May 1943, the RAF's Bomber Command began the formation of a new squadron, codenamed Squadron 'X'.
A team of bomber and nightfighter veterans was assembled from every part of the Commonwealth to deliver a very special payload - the brainchild of inventor Barnes Wallis.
These airmen have trained in secret for months in low-altitude flying and bombing without knowing their final purpose.
The Target: Three hydroelectric dams deep within the heartland of Industrial Germany.
The Delivery Method: 19 Lancaster Bombers, flying below radar.
The Payload: 'Upkeep', a four-ton bomb designed to skim over water like a skipping stone.
Fly and shoot your way through the rivers of the Ruhr Valley while reliving this incredible feat of daring, brilliance and skill.
Raid on the Ruhr appears in the following lists: