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 father Amias, who has grown quite peculiar in the years since she left home. Before she can find out what's troubling him, 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. The barrister doesn't notice, but Jane finds it alarming. How can a bird change the label on a bottle or alter the sketch of a footprint?
Things only get 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 knits hair into spell-stopping nets.
Either Jane is caught in a very strange dream or Ayreford is thickly inhabited by the Fair Folk, playing out their ancient rivalries through the unsuspecting townspeople. But Jane can't think about that, either way. Not yet. She'll do whatever she must, however bizarre, to save her father from hanging. And then she'll get the truth from him -- or possibly his cat.