 Montmartre in the summertime. A group of street urchins idles outside while the other kids of the neighborhood are away on holiday.To keep the gang busy, Pivolo, their leader, has an idea : they are going to kidnap Aunt Faguet s doggy. Just for the fun of it. A few days pass after the crime is accomplished and one of them suddenly realizes that a reward is being offered by the aunt to anyone who would bring her her pet back. Mademoiselle Hélène, the kind-hearted social worker, does it for them and gives them the reward money, which is instantly exchanged for lollipops, nougat and merry-go-round and cinema tickets. So, why not continue? That s what they do, abducting several dogs, until they realize they are becoming ... too rich! They can t buy themselves luxurious gifts or else their parents are bound to suspect something. Instead, they decide to do good by helping poor people around them. One day, Pierrot, a member of the gang, gets run down by a cyclist and becomes blind. Only a costly operation can heal him. Well, the solution is obvious : increase their illegal activities. But the police are beginning to smell a rat.