Iris Hollow and her two older sisters are unquestionably strange. Ever since they disappeared on a suburban street in Scotland as children only to return a month a later with no memory of what happened to them, odd, eerie occurrences seem to follow in their wake. And they're changing. First, their dark hair turned white. Then, their blue eyes slowly turned black. They have insatiable appetites yet never gain weight. People find them disturbingly intoxicating, unbearably beautiful, and inexplicably dangerous.

In the lands of Bethel, where the Prophet's word is law, Immanuelle Moore's very existence is blasphemy. Her mother's union with an outsider of a different race cast her once-proud family into disgrace, so Immanuelle does her best to worship the Father, follow Holy Protocol, and lead a life of submission, devotion, and absolute conformity, like all the other women in the settlement. But a mishap lures her into the forbidden Darkwood surrounding Bethel, where the first prophet once chased and killed four powerful witches.

Each spring, Ithaca condemns twelve maidens to the noose. This is the price vengeful Poseidon demands for the lives of Queen Penelope’s twelve maids, hanged and cast into the depths centuries ago. But when that fate comes for Leto, death is not what she thought it would be. Instead, she wakes on a mysterious island and meets a girl with green eyes and the power to command the sea. A girl named Melantho, who says one more death can stop a thousand.

Carolyn's not so different from the other human beings around her. After all, she was a normal American herself once. That was a long time ago, of course - before the time she calls "adoption day", when she and a dozen other children found themselves being raised by a man they learned to call Father.

As a half-goddess possessing magic, Yaga is used to living on her own, her prior entanglements with mortals having led to heartbreak. She mostly keeps to her hut in the woods, where those in need of healing seek her out, even as they spread rumors about her supposed cruelty and wicked spells. But when her old friend Anastasia—now the wife of the Tsar, and suffering from a mysterious illness—arrives in her forest desperate for her protection, Yaga realizes the fate of all of Russia is tied to Anastasia’s. Yaga must step out of the shadows to protect the land she loves.