British airmen embark on a daring mission to destroy a heavily fortified German fuel manufactory in Norway, and to ensure success the RAF pilots have to bomb an overhanging cliff to collapse it on to the building. The plan threatens to unravel, however, when a Norwegian freedom fighter plotting a land attack to coincide with the air strike is captured by the Nazis. Second World War drama, starring Cliff Robertson, George Chakiris, Donald Houston and Harry Andrews.

When Norwegian resistance leader Lieutenant Erik Bergman reports the location of a German V-2 rocket fuel plant, the Royal Air Force's 633 Squadron is assigned the mission to destroy it. The plant is in a seemingly-impregnable location beneath an overhanging cliff at the end of a long, narrow fjord lined with anti-aircraft guns. The only way to destroy the plant is by collapsing the cliff on top of it.