Dr. Tamsin Rivers, when a door opens in her basement to reveal an exact copy of her, one that’s sweet and biddable where she’s calculating and cruel, must hold herself together long enough to figure out what the double wants from her—and where the mysterious door leads.

"Nineteen years old, broke, and effectively an orphan, Magnolia doesn't have much to look forward to. She feels stuck and haunted: by her overdrawn bank account, by her predatory landlord, by the ghost of her late grandmother Mama Brown. One night while working at her dead-end job, a mysterious, slick stranger named Cotton walks in and offers to turn Magnolia's luck around. He offers her a lucrative "modeling" job at his family's funeral home. Magnolia...