Like most of the William books it has no continuous narrative, but consists of separate independent short-stories. The stories are as follows:
William is given a book entitled Things a Boy Can Do and annoys his entire household by trying to carry out its instructions, along with Jimmy, a cousin with a sister called Barbara.
- Rice-Mould (The first ever story, c.1919)
In order to impress the little girl next door, William attempts to steal cream blancmange from the household kitchen.
William befriends a mysterious stranger who claims to be a war veteran, but who is quite obviously a criminal.
A Quixote-esque tale in which "Sir William" and his faithful "squire" Ginger set out to rescue a "damsel in distress".
William takes up taxidermy as a hobby and puts a dead frog that he wishes to stuff in Uncle George's tea for 'Tannin'.
William has a rival for the affections of Joan.
William arranges a "psychic experience" for his cousin Mildred.
William is chosen as attendant to the May Queen (Evangeline Fish, a girl despises) in a school pageant, but he has bigger ambitions.
William takes revenge on his family by pretending to run away from home.
William "helps" the removal men when his family moves house and gets stuck on the roof.
Mr. Brown goes to the seaside for a "rest cure" but unfortunately has to endure William's company.
William is inspired to lead a better life, but decides not to start just yet and on his 'last day' of his 'old life', crashes a caravan into a donkey cart.
- William and the Ancient Souls
A grown-up friend of William has his life made unendurable by a new neighbour who is the President of the society of Ancient Souls.
William and Joan deliver a Christmas feast to a poor family whose man of the house has just been released from 'The Nick'
