Captain Keith Mallory is an officer with the British Long Range Desert Group. He has been operating behind the lines in the mountains of Crete for two years when he is suddenly called in for a secret assignment. The details, when he gets them, are less than reassuring. Mallory is to lead a small team of specially chosen men and infiltrate the German held Greek island of Navarone.
There are 1200 Allied troops stranded on the nearby island of Kheros. Literally surrounded by the enemy, their only possibility of rescue is by sea. The problem is, the fortress on Navarone has been outfitted by the Nazis with two huge artillery guns which can hit and sink any naval vessels attempting rescue. In order to reach Kheros, the guns on Navarone are going to be taken out, but the island is so heavily fortified that it seems an impossible task. There has already been a disastrous attempt made by air, which resulted only in the loss of a lot of valuable men and planes.