William Brown has a good-intentioned yet naughty nature that continuously challenges his family's patience. He and his friends make big plans at their shed club and so get involved in various adventures : pursuing a secret agent, weedening a rich woman's garden in the hope of getting some money for candy, helping secret service detectives, looking for an exchanged baby sister and deactivating a dangerous bomb hidden in a suitcase. That, of course, from their point of view. Not forgetting in the meantime to campaign for William's father -or against him?. Punishment is always near, but after all he didn't mean any harm. Well, you know, it's - just William.