In the heart of Black Country, England, Cradle Cross is a town out of time, an isolated pocket of the country whose customs and views have remained intact since medieval times. In 1933, the town is still reeling from the Great War and dominated by a button factory in terminal decline. Into this exotically grim environment arrives Isa Fly, a mysterious white-haired young woman from the coast. Isa is a magnetic presence who exerts a romantic pull on everyone she meets. Ruby Tailor, motherless and thirteen years old, is instantly drawn to her; as is Captin, the proprietor of the local chip shop, a fifty-year-old bachelor and father figure to Ruby; and Truda Blick, the Oxford-educated spinster who's inherited the failing button factory. But Isa is viewed with increasing suspicion by the tight-knit women of Cradle Cross, who come to see her as the cause of the town's accelerating misfortunes and, ultimately, fear her as a witch.