Kay Harker lives in an old house in the country, looked after by his unpleasant governess, Sylvia Daisy Pouncer. One night Kay’s great-grandpapa Harker, a sea captain, steps out of his portrait to tell him about a stolen treasure, and Kay embarks on a quest to recover it. Along the way he is helped by the Midnight Folk, including animals such as Nibbins the cat, Rollicum Bitem the fox and his lost toys, as he uncovers a coven of witches and has to foil the evil Abner Brown.

The Midnight Folk is full of adventure as well as nostalgia for a bygone age and childhood. There are also verses of song and poetry throughout - John Masefield was a former Poet Laureate.