Elizabeth is devastated when her boyfriend of ten years leaves her for someone else. After a night of drowning her sorrows leads to an unexpected one-night stand, she finds herself pregnant, alone and vulnerable.

Meanwhile Helen discovers she has an older sister who was adopted as a baby. Bored with her privileged life and driven by a need to gain her parents’ approval, Helen sets out to find her sister and reunite her with their mother. When her search leads her to Elizabeth the two women’s lives become entwined, with potentially catastrophic consequences for both of them.