1950s schoolboy William Brown and his gang the Outlaws are forever getting in and out of scrapes,including trespassing at Croombe Hall,recently acquired by parvenu table sauce tycoon Mr. Bott and his cheery,expansive wife. They have a lisping,sweetly beribboned six year old daughter Violet Elizabeth,with whom a reluctant William is encouraged to play. He is mortified when she shows up in front of the gang demanding to join in their games,getting herself joyfully covered in mud. Her distraught mother reports her missing and,when William and the Outlaws return her, they...
A visit from African explorer Uncle Neville prompts William into giving a lecture on 'Interestin' Animals' but with only a dead mouse as a prop he finds himself woefully short of creatures to illustrate his talk. Until sister Ethel's rival boy-friends George and Hector both bring parrots to cheer her up when she has suspected measles. Finding the birds left in the garden lead William to believe that a well-wisher has brought them for his talk but when the boys want their gifts back they find that William drives a very hard bargain.
Already unhappy as his friend Bob Andrews,the Botts' gardener,has been sacked,a bad school report does nothing to lift William's spirits. Efforts to forge a better report are no more successful than his initial attempt to blackmail Mr. Bott into reinstating Bob. However Mr. Bott's failure to keep up the strict slimming regime imposed by his wife plays into William's hands - as does the opportunity to rescue visiting Aunt Augusta,lost in the woods, by creating a unique paper trail.
William is not keen to take part in a school competition to stage the best scene from 'Hamlet' until he sees it as an opportunity to impress the tomboyish Dorinda,so he is annoyed when class swot Dalrymple gets the name part and he is relegated to being a spear carrier. With Dorinda in the opening night audience and only minutes to go before the curtain rises William has to think fast to make an impression the whole audience will remember.