East Anglia, 1645. Martha Hallybread, a midwife, healer, and servant, has lived peacefully for more than four decades in her beloved seaside village of Cleftwater. Having lost her voice as a child, Martha has not spoken a word in years. One autumn morning, a sinister newcomer appears in town. The witchfinder, Silas Makepeace, has been blazing a trail of destruction along the coast, and now has Cleftwater in his sights. His arrival strikes fear into the heart of the community. Within a day, local women are being captured and detained, and Martha finds herself a silent witness to the hunt. Powerless to protest, Martha is enlisted to search the accused women for "devil's marks." She is caught between suspicion and betrayal; between shielding herself or condemning the women of the village. In desperation, she revives a wax witching doll that belonged to her mother, in the hope that it will bring protection. But the doll's true powers are unknowable, Martha harbors a terrible secret, and the gallows are looming...