Flora is a new mom enamored of her baby girl, Iris, who has arrived a few weeks early. But with her husband still deployed, Flora must navigate the newborn stage alone. As the sleepless nights pass in the loneliness of their half-empty home, the edges of her reality begin to blur.

Just as Flora becomes convinced she is losing her mind, a surprising guest shows up to help: Flora's own mother, to whom she hasn't spoken in years. Can they mend their fraught relationship? Or is there more that Flora's mother isn't telling her about the events that led to their estrangement?

As stranger and scarier events unfold, Flora begins to fear that her mother's secrets have allowed something truly evil to enter her home. She must decide: is her hold on reality slipping dangerously away? Or is she, in fact, the only thing standing between a terrifying visitor and her baby?