Keith Mallory, a mountain climber from New Zealand, must infiltrate the Aegean island of Navarone, and destroy the guns on the German fortress there, in order to save the lives of 1,200 British soldiers. He gets a team together, boards a small craft, and heads to Navarone. On the way there, his small ship is nearly destroyed in a storm, and he then must climb a 400 foot sheer cliff in the middle of the storm. In the process, they lose all their food, and one of their team members breaks his leg. The next section of the book describes their working their way over to the other side of the island of Navarone, while dodging German patrols, and nursing their wounded comrade. They meet up with the resistance movemment on Navarone, but the Germans keep on their trail. They soon find out that one of the resistance men was giving them away and have nearly half their team captured. They break them out and blow up the guns, and then are able to escape onto a waiting British submarine