During the Second World War, British soldier Stanley Moss arrives on Crete to join Major Patrick 'Paddy' Leigh-Fermor. Paddy and Captain Sandy, both undercover British agents on the island, take Moss to a local town, where they sing, drink and dance with the villagers before being offered shelter for the night. Paddy tells Moss that he has specially requested his presence to assist an audacious plan to kidnap General Kriepe, Commander-in-Chief of the 30,000 German troops occupying the island. Kriepe is to be removed to Cairo, an act that will humiliate the German forces while depriving them of a forceful leader. The next day, Moss, Paddy and several Cretan partisans examine the General's daily route and plan the ambush of his Mercedes. They return at night and lie in wait. After several false alarms, the Mercedes approaches. Paddy and Moss halt the car, knock out the driver and commandeer the vehicle. Paddy takes the General's hat as a disguise and they begin their tense journey. The kidnappers successfully pass numerous German posts and arrive at the General's villa. To the surprise of the guards waiting at the gate, the car speeds on past the house and successfully reaches open countryside. Back at the villa, the alarm is raised.

Paddy respectfully returns General Kriepe's hat, before disposing of his car. While the men and their hostage set off into the hills, the Germans begin the search for their commanding officer. They issue a statement demanding that the islanders turn in the kidnappers and threatening reprisals if they do not. Moss is angered to read this, as he left a note informing the Germans that the kidnapping was a military operation. Paddy sends a message to Captain Sandy asking him to secure a boat, while Moss notices that the General's Iron Cross is missing. When he asks the General what has happened to it, Kriepe expresses surprise at his loss. However, as they set off again, he deliberately leaves his hat behind, leaving a trail for his rescuers to follow.

As the men rest that evening, a young boy, Nico, brings them a message. German troops are on the move and the kidnappers are likely to be cut off from the sea if they do not resume their journey immediately. As they prepare to leave, Nico admires the General's boots and expresses his desire to have a pair of his own. Paddy promises that one day he will. The men continue their journey through the night, with the General ignominiously mounted on a donkey. When they reach the next village they receive a message from Captain Sandy, who has arranged for a ship to collect the kidnappers and their captive. The boat will wait in a secluded cove every night for three nights. As they only have one night left, Paddy decides they must risk marching by day, but when they eventually get to the beach, a large number of German troops have already arrived and set up camp.

While Paddy ponders what to do, General Kriepe attempts to bribe Nico. He gives him a gold coin and tells him to offer this to the soldiers on the beach in exchange for the boots he so desperately wants. Nico runs down to the beach and the General tells Paddy that he has been betrayed. Instead of leading the soldiers to the kidnappers, however, Nico sends them in a different direction, leaving the beach clear for the kidnappers to rendezvous with their boat.

Cretan partisans join them on the shore, jubilant after successfully ambushing the German troops and rescuing Nico, who they now treat as a hero. After what he has done, it is decided that Nico should leave Crete for the duration of the war. Safely on the boat, Paddy returns the buttons, medals and hat that the General had thought he was covertly leaving behind as they traversed Crete. Recognising his defeat, the General congratulates Moss and a bare-footed Paddy on their professional execution of his kidnapping. On deck, Nico proudly stands to attention in his newly acquired boots.