When a mini bomb is dropped by accident from an American plane over Spain, the "spies" from various foreign countries converge in an attempt to find it. Leading the pack is a young Englishman named Cliff, who arrives with his singing group, called the Shadows. Cliff and the Shadows hitchhike to a hotel which, they find deserted. With the help of a local girl named Emelia (Ventura), they decide that it is in their interest to locate the bomb and hand it over to the American troops, who have moved in on a similar mission. But Mr. X (Le Mesurier), the sinister representative of a foreign power, has the same idea and blackmails Colonel Roberts (Morley), the English manager of the hotel to do the job for him. Burke (Stark), the hotel clerk, is also in on the scheme. Before all the confusion and skulduggery ends, Cliff and the Shadows have uncovered the bomb for the Americans, and Cliff has enjoyed a romantic liaison with Emelia.