All three episodes of the documentary series retelling the preparation for and execution of the 1943 RAF mission Operation Chastise. Presented by Dan Snow with contributions from other historians and former RAF pilots, we follow 617 Squadron leader Guy Gibson as he is asked to lead the mission and must assemble and train a team of 133 expert pilots. The struggles Barnes Wallis faced while developing his bomb and the launch of the attack on Germany's dams also feature.