Lottie and Nick once had a dream marriage, but a series of failed IVF attempts has left Lottie feeling insecure, and her paranoia is further stoked by the arrival of a new starter at Nick's firm. Tasha is the spitting image of a younger, more attractive Lottie, and Nick is paying her a lot of attention... But then Lottie discovers she's pregnant. A surprise getaway to their country cottage to celebrate Nick's birthday will provide the perfect backdrop to give him the news and start to heal the rifts in their relationship. Then, on the eve of Nick's birthday, Lottie goes into the cellar, and what she finds makes her question everything.
Because there, in the corner of the cellar, is the body of a young woman. A young woman who looks just like Lottie...
