Hundreds of feet beneath the ocean's surface, a graveyard waits. Years ago, the SS Arcadia vanished without a trace during a routine voyage. Though a strange, garbled emergency message was broadcast, neither the ship nor any of its crew could be found. Sixty years later, its wreck has finally been discovered more than three hundred miles from its intended course: a silent graveyard deep beneath the ocean's surface, eagerly waiting for the first sign of life.

Struggling with money, raising a child alone, and fleeing a volatile ex, Jess McMachen accepts a job caring for an elderly patient. Flo Gardner–a disturbed shut-in and invalid. But if Jess can hold this job down, she and her daughter, Izzy, can begin a new life. Flo's vast home, Nerthus House, may resemble a stately vicarage in an idyllic village, but the labyrinthine interior is a dark, cluttered warren filled with pagan artefacts.

Abby Ward lives in a town haunted by disappearances. People vanish, and when they're found, their bodies have been dismembered and sewn back together in unnatural ways. But is it the work of a human killer…or something far darker?

Joe works at a facility that performs human experimentation. His work just followed him home. The government wanted to unlock hidden abilities in the human mind. They put subjects in extreme sensory deprivation. All the test subjects went violently insane. But the research continued. Today it has been perfected. Almost perfected. 

Clare remembers the cold. She remembers abandoned cars and children's toys littered across the road. She remembers dark shapes in the snow and a terror she can't explain. And then... nothing. When she wakes, aching and afraid in a stranger's gothic home, he tells her she was in an accident, a crash in the snow. He claims he saved her. Clare wants to leave, but a vicious snowstorm has blanketed the world in white, trapping them together, and there's nothing she can do but wait.