In Paris 1910, mother cat Duchess and her three kittens, Berlioz, Marie and Toulouse live with retired opera diva Madame Adelaide Bonfamille, and her English butler, Edgar. One day while preparing her will with lawyer Georges Hautecourt, Madame declares her fortune to be left to her cats until their deaths, and thereafter to Edgar. Edgar hears this through a speaking tube, and plots to eliminate the cats. Therefore, he sedates the cats by putting sleeping pills in a milk mixture intended for them, and enters the countryside to abandon them. There, he is ambushed by two hounds named Napoleon and Lafayette, and the cats are stranded in the countryside, while Madame Adelaide, Roquefort the mouse and Frou-Frou the horse discover their absence.