The Dawson family visit their Aunt Agatha who lives in a North Yorkshire village, and the children find she is as odd as they have been led to understand. Agatha encourages the children to take an interest in the natural world, by visiting the large Wickham wood that lies close to her house. They find the forest to have a spooky reputation and it to be home to a community of strange animals, most of whom are suspicious of people, whom they refer to as oomans. A notable exception is the academic Professor Wisefeather, an owl who befriends the youngest child Phillipa as he senses in her a latent power of witchcraft. The Professor is a senior member of the wood's animal community, known as the Woodland folk, and he is also acquainted with Aunt Agatha who is a practising witch and one of the few people who is aware of the animal community and its fear of human beings. Linked to this is a story from the animals folklore concerning something of great importance and value hidden in the forest long ago, the discovery of which will attract the humans into the wood in huge numbers and change the Woodland folk's way of life forever. When Phillipa finds an old coin in her aunt's garden it causes panic among the animals who fear it will result in renewed interest in the possibility of something concealed there. Not all of the animal community are altruistically concerned, a criminal gang of birds led by the magpie Slippery Beak, want the thing of great value revealed so they can steal some of it at least. The discovery of an old document in Agatha's house provides further evidence for something hidden in the forest, so the witch decides to introduce Phillipa to the Woodland folk given that she has the gift, which meets with a mixed reaction from them. Nevertheless, they grudgingly accept her but the animals are collectively resistant to Agatha's attempt to investigate the mystery, some of them know more about it than they are letting on. The gang of avian criminals form an alliance with two human villains and attempt to burgle the witch's house, believing there to be something in the building which will lead them to the thing of value, they are thwarted by a repulsion spell. An ancient stone inscription found in the wood provides definitive proof that something lies there, which results in a formal investigation by professional archaeologists. Phillipa uses her developing magic powers to defend her family against a gang of bullies they run into, which puts Agatha in an awkward position, having to explain away the results of her spell casting to the rest of the suspicious family. Slippery Beak's plan to recruit other witches to gain revenge on Agatha backfire when they curse him and his associates for trying to mislead them. The archaeological exploration being carried out reveals what exactly lies hidden in Wickham wood, with both humans and animals nervously awaiting the outcome.