When the swindler La Spada and his accomplice José come out of jail in Madrid, they decide to pull a really great swindle: nothing less than to discover and sell a third picture of the famous Goya's Maya, the^ÔMaya in camisòn^Ô (Maya with a night-gown). They engage the renowed Scorcelletti who can imitate any picture and who lives in Rome. Afterwards, with the help of the beautiful Eva, they convince the celebrated art critic Francisco Montiel of the existance of a third Maya and let him find the picture. When the swindlers are on the point of selling the faked maya to an American millionaire, Scorcelli comes back from Rome to sell one of his six other maya pictures.