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 forty, 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 whether 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, including Gretchen's gentle and thoughtful husband Howard, who mostly believes his wife, and their quirky and charming daughter Margaret, who becomes a sort of surrogate child for Jean. Gretchen, too, becomes a much-needed friend in an otherwise empty social life. Jean cannot bring herself to discard what seems like her one chance at happiness, even as the story that she is researching starts to send dark ripples across all their lives...with unimaginable consequences.