: The mother, Keira (Cuthbert), discovers that the house's former owner was a physicist who used alchemical math to turn the house into a gateway for a demonic entity named Leviathan (or Baphomet). Critical Review: "Arithmetic of Agony"

The film is a supernatural thriller that takes the "haunted house" trope and injects it with a unique, cerebral twist: .

: After moving into an old Irish estate, the Woods family's teenage daughter, Ellie, disappears while counting the steps down to the dark basement during a power outage. She reaches ten steps—the actual number—but her voice on the phone keeps counting into the hundreds as she vanishes into thin air.