Following a traumatic event in London, Kirsty Woodhouse packs up her family and moves back to her native Wales. There she sets up her new home with her husband and two young daughters, and goes into business with her difficult mother managing a guesthouse in the Brecon Beacons. But when the guesthouse is ready to be occupied, Kirsty encounters the last person she ever expected to see: her estranged cousin Selena. It has been seventeen years since they last talked—when Selena tore everything apart between them. Why has she chosen now to walk back into Kirsty's life?

Grace Holloway keeps to herself. Since narrowly escaping death at the hands of the man who kidnapped her, she’s thrown herself into the small inn she runs in Rock Harbor, Maine. It’s quiet, quaint and, in the off-season, completely isolated—the perfect place for Grace to keep her own secrets. But Grace isn’t the only one with something to hide, and Rock Harbor isn’t just a sleepy vacation town. Someone is taking young women—girls who look an awful lot like Grace did when she was kidnapped so many years ago.

At loose ends after the devastating death of her mother, Una Richardson responds to an advertisement for a ladies’ companion, a position that leads her into the wealthy, secluded world of Mrs. Elspeth McKenzie. But Elspeth's home isn’t the comforting haven it seems. Kathryn, her cold and bitter daughter, resents Una's presence. More disturbing is evidence suggesting two girls lived here before her.

No one knows exactly when it began or where it originated. A terrifying new plague is spreading like wildfire across the country, striking cities one by one: Boston, Detroit, Seattle. The doctors call it Draco Incendia Trychophyton. To everyone else it's Dragonscale, a highly contagious, deadly spore that marks its hosts with beautiful black and gold marks across their bodies - before causing them to burst into flames. Millions are infected; blazes erupt everywhere. There is no antidote. No one is safe.

For 12-year-old Cora Landry and her friends Violet and Jordyn, it was supposed to be an ordinary sleepover - movies and Ouija and talking about boys. But when they decide to sneak out to go to the abandoned rail yard on the outskirts of town, little do they know that their innocent games will have dangerous consequences. Later that night, Cora Landry is discovered on the tracks, bloody and clinging to life, her friends nowhere to be found. Soon, their small rural town is thrust into a maelstrom. Who would want to hurt a young girl like Cora - and why?