In the small mountain town of Jasper, North Carolina, June Farrow is waiting for fate to find her. The Farrow women are known for their thriving flower farm—and the mysterious curse that has plagued their family line. The whole town remembers the madness that led to Susanna Farrow’s disappearance, leaving June to be raised by her grandmother and haunted by rumors.

After centuries of sleep, the gods are warring again. But eighteen-year-old Iris Winnow just wants to hold her family together. Her mother is suffering from addiction and her brother is missing from the front lines. Her best bet is to win the columnist promotion at the Oath Gazette. To combat her worries, Iris writes letters to her brother and slips them beneath her wardrobe door, where they vanish—into the hands of Roman Kitt, her cold and handsome rival at the paper.

Cambridge professor Emily Wilde is good at many things: She is the foremost expert on the study of faeries. She is a genius scholar and a meticulous researcher who is writing the world’s first encyclopaedia of faerie lore. But Emily Wilde is not good at people. She could never make small talk at a party—or even get invited to one. And she prefers the company of her books, her dog, Shadow, and the Fair Folk to other people.

Charlie Hall has never found a lock she couldn’t pick, a book she couldn’t steal, or a bad decision she wouldn’t make. She's spent half her life working for gloamists, magicians who manipulate shadows to peer into locked rooms, strangle people in their beds, or worse. Gloamists guard their secrets greedily, creating an underground economy of grimoires. And to rob their fellow magicians, they need Charlie Hall.

Opal is a lot of things—orphan, high school dropout, full-time cynic and part-time cashier—but above all, she's a determined to find a better life for her younger brother Jasper. One that gets them out of Eden, Kentucky, a town remarkable for only two things: bad luck and E. Starling, the reclusive nineteenth century author of The Underland, who disappeared over a hundred years ago. All she left behind were dark rumors—and her home. Everyone agrees that it’s best to ignore the uncanny mansion and its misanthropic heir, Arthur. Almost everyone, anyway.