THE STORY PLOTS
The year is 1910. On an autumn day in Paris, a mother cat named Duchess and her three kittens ― Marie, Berlioz and Toulouse ― live in the mansion of retired opera singer Madame Adelaide Bonfamille, along with her English butler, Edgar Balthazar. She early on settles her will with her lawyer, Georges Hautcourt – an aged, eccentric old friend of hers – stating that she wishes the “faithful” Edgar to look after her beloved cats until they die. Only then will he inherit the fortune himself. Edgar hears this from his own room and believes he will be dead before he inherits Madame Adelaide’s fortune, and so plots to remove the cats from a position of inheritance (clearly not thinking about how he would be essentially in control of the fortune, despite having to take good care of them).
Edgar sedates the cats by putting an entire bottle of sleeping pills into their food and then heads out into the countryside to dispose of them. However, two hound dogs named Napoleon and Lafayette attack him. After the conflict, Edgar escapes, leaving behind his umbrella, hat, the cats’ bed basket and the sidecar of his motorcycle in the process. The cats are left alone and afraid in the countryside, while Madame Adelaide, Roquefort the Mouse and Frou Frou the horse discover their absence. In the morning, Duchess meets an alley cat named Thomas O’Malley, who offers to guide her and the kittens to Paris.
They have a struggle returning to the city, briefly hitchhiking on the back of a milk cart before being unfortunately chased off by the driver. Marie subsequently falls into a river after a train roars down the tracks and is saved by O’Malley. They then meet a pair of British white geese, Amelia and Abigail Gabble, who are travelling to Paris. The group heads off, marching like geese, until they reach Paris and come across the girls’ drunken Uncle Waldo. Abigail and Amelia then depart to take Waldo home. Travelling across the rooftops of the city, the cats meet Scat Cat and his band, close friends to O’Malley, who perform the song “Everybody Wants to Be a Cat“. After the band has departed and the kittens lie in bed, O’Malley and Duchess spend the evening on a nearby rooftop and talk, while the kittens listen at a windowsill. The subject of their conversation is the question of whether Duchess can stay and be with Thomas.
Reluctantly, Duchess sadly turns him down, largely out of loyalty to Madame Adelaide, pointing out that Madame really does love her and her kittens – some cuts to Madame Adelaide show that she truly is very unhappy without her cats, and feeling very much alone. The listening kittens are disappointed, although they too wish to go home. Edgar, meanwhile, retrieves his sidecar, umbrella, and hat from Napoleon and Lafayette with some difficulty.
The cats make it back to the mansion, whereupon O’Malley departs sadly after he and Duchess have a heartfelt farewell moment. Edgar sees Duchess and Kittens coming and suddenly captures them, places them in a sack and briefly hides them in an oven. The cats tell Roquefort to pursue O’Malley and get help. He does so, whereupon O’Malley races back to the mansion, ordering Roquefort to find Scat Cat and his gang. Edgar places the cats in a trunk which he plans to send to Timbuktu, Africa so they can never come back. O’Malley, Scat Cat and his gang, and Frou-Frou all fight Edgar, while Roquefort frees Duchess and kittens. In the end, Edgar is tipped into the trunk, locked inside, and sent to Timbuktu himself. Madame Adelaide’s will is rewritten to exclude Edgar and include O’Malley. She starts a charity foundation providing a home for all of Paris’ stray cats. The grand opening thereof, to which most of the major characters come, features Scat Cat’s band, who perform a reprise of “Everybody Wants to Be a Cat”.