The London suburb of Croydon, 1964: Helen Hansford is an art therapist at the Westbury Park psychiatric hospital, where she has been having a rebellious love affair with her colleague Gil, a dashing but married doctor. One spring afternoon, they receive a call about a disturbance at a derelict, vine-covered Victorian house. There the police find a mute, 37-year-old man called William Tapping. It appears he lives in the old house with his elderly, frail aunt, who expires as soon as she’s admitted to the hospital. No one knows why William has been shut away for decades, unseen by neighbors. When it emerges that William is not only sane but a talented artist, Helen comes to see him as something of a personal project. But as she tries to solve the puzzle of the Hidden Man’s past, Helen’s own carefully constructed life of secrets begins to unravel.

1957: Jean Swinney is a feature writer on a local paper in the southeast suburbs of London. Clever but with limited career opportunities and on the brink of 40, Jean lives a dreary existence that includes caring for her demanding widowed mother, who rarely leaves the house. It’s a small life with little joy and no likelihood of escape. That all changes when a young woman, Gretchen Tilbury, contacts the paper to claim that her daughter is the result of a virgin birth. Jean seizes onto the bizarre story and sets out to discover if Gretchen is a miracle or a fraud. But the more Jean investigates, the more her life becomes strangely (and not unpleasantly) intertwined with that of the Tilburys.