Two dolls, Hugo & Henriëtte, grow to human size after eating sweets from a magic box they find in the toy store. And go out on an adventure. The store keeper asks the police to find them and bring them back.
Hugo & Henriette learn the rules of traffic. Meanwhile the storekeeper is very concerned about his two favorite dolls. Zwarte Piet comes round with a large list of toys needed by Sint Nicholaas.
Hugo and Henriëtte mind the store when the shopkeeper goes to the dentist. Then the police officer, who is still looking for the missing dolls comes round. Henriette decides to go off on her own and meets a sailor-doll who takes her to a another toy store.
The policeman has grown to a giant size by eating enlarging sweets and Hugo promises to find a cure. A rival toy store owner is looking for his missing Flip the sailor doll and decides to take Henriëtte to his shop instead.