Force 10 from Navarone is a 1978 war film loosely based on Alistair MacLean's 1968 novel of the same name. It is a sequel to the 1961 film The Guns of Navarone. The parts of Mallory and Miller are played by Robert Shaw (who died before the film was released), and Edward Fox, succeeding in the roles originally portrayed by Gregory Peck and David Niven. It was directed by Guy Hamilton and also stars Harrison Ford, Carl Weathers, Barbara Bach, Franco Nero (in a "plastic surgery" role previously played by Tutte Lemkow), and Richard Kiel.
The film gets its title from the Alistair MacLean book of the same name, but bears so little resemblance to the novel that MacLean loosely adapted part of the screenplay into his 1982 book Partisans.
Plot
In 1943, Major Keith Mallory and Sergeant Donovan "Dusty" Miller from British Commandos are sent to find and eliminate Nicolai, a German spy who previously betrayed the Navarone mission to the Germans and is now believed to have successfully infiltrated the Yugoslav Partisans as "Captain Lescovar". To get to Yugoslavia, the two men pair with "Force 10", an American sabotage unit led by US Army Rangers Lieutenant Colonel Mike Barnsby and steal a bomber. They are joined by Weaver, a Medical Corps sergeant arrested by the Military Police, and escape, only to be shot down by the Luftwaffe. Only Barnsby, Mallory, Miller, Weaver, and Lieutenant Doug Reynolds (Angus MacInnes) escape the crippled plane.
The survivors come upon a band of men they believe to be partisans but are later revealed as collaborationist Chetniks led by Captain Drazak. Taken prisoner, they tell the German commander in control of the area, Major Schroeder, that they are deserters. To keep Schroeder from opening Miller's explosives suitcase, Mallory claims it contains the new drug "penicillin" which will spoil if exposed. The next morning the prisoners are told that Schroeder has opened the case, finding it full of firewood. They improvise an excuse, "admitting" they buried the samples. Schroeder sends Barnsby and Mallory to retrieve them under the guard of his concubine Maritza and three soldiers. Miller, Weaver, and Reynolds are left in camp.
Far from camp, Maritza kills the Germans, revealing herself to be a partisan and the person who hid the explosives. She directs Mallory and Barnsby towards the partisan camp under the command of her father, Major Petrovich. Mallory and Barnsby escape and meet a patrol of real Yugoslav partisans led by Lescovar, who has gained Petrovich's trust. Mallory and Barnsby are taken to the camp, which lies near a hydroelectric dam. An arch bridge spanning the river ravine is set to be used by a German force for an impending assault on the partisans, who have been unable to destroy the bridge. Barnsby reveals that the bridge is Force 10's target.
Mallory convinces Petrovich to mount a rescue mission of demolitions expert Miller, using Lescovar and Marko, a loyal partisan. The four re-enter the camp at night, with Mallory and Barnsby posing as captives, and Lescovar and Marko disguised as Chetniks. Drazak discovers that Maritza must have helped Miller and Mallory escape, and begins beating her viciously. Schroeder and Reynolds are killed in a gun battle, but the others escape with a badly beaten Maritza and the recovered explosives.
Miller reveals that the bridge is impregnable, which Barnsby refuses to accept. Mallory hits upon the idea of destroying the upstream dam, to use the sudden onrush of millions of gallons of water to destroy the bridge. A night-time air drop is arranged to replace Force 10's lost supplies, but Lescovar, revealed to be the saboteur, calls in German planes to stop the drop. Maritza catches Lescovar in the act, but he kills her before she can warn the others, and German planes bomb the illuminated drop zone, killing numerous partisans.
Petrovich, angered by the botched air drop, orders the men to be sent to Marshal Tito's headquarters for transport back to Italy. Accompanied by Lescovar and Marko, the team instead infiltrates the German marshaling yards at Mostar to steal explosives. Lescovar again betrays them, alerting a German sergeant to their presence. Marko sacrifices himself to save the others, who escape with Lescovar aboard a train leaving for Sarajevo. Lescovar is questioned by the others, who have grown suspicious of him. Lescovar initially denies the accusations, but gives himself away and is shot dead by Barnsby, who then asks Mallory to return the favour by helping him accomplish Force 10's mission.