Welcome to Ayreford in 1591, where cats can talk and fairies are real.
Jane Moone leaves her thriving practice as a cunning woman in London to return to Ayreford to care for her aging father Amias. She's scarcely settled in when her only client's husband is murdered. The tailor is found in his workshop covered in red spots with a bottle of tonic from Moone's apothecary near at hand. A rival cunning man accuses Amias of poisoning him and the old man is arrested.
Jane knows her father is innocent. She joins forces with a handsome barrister to study the scene. They find evidence to support Amias, but each item is altered when a blackbird sings. That bird has been following them everywhere. Then things turn even more peculiar. Amias's ginger cat gives Jane wise counsel, a frog-pond fairy claims to know her long-lost mother, and a hedge witch shows Jane how to stop the malevolent fairy behind all the glamors.
Either Jane is caught in a very strange dream, or Ayreford is thickly inhabited by the Fair Folk. Either way, Jane must do whatever she can, however bizarre, to save her father from hanging. Then she'll get the truth from him - or possibly his cat.