In the winter of 1956 pregnant young Ivy is sent in disgrace to St Margaret's, a home for unmarried mothers in the south of England, run by nuns, to have her child. Her baby daughter is adopted. Ivy will never leave. Sixty years later, journalist Samantha stumbles upon a series of letters from Ivy to her lover, pleading with him to rescue her from St Margaret's before it is too late. As Sam pieces together Ivy's tragic story, terrible secrets about St Margaret's dark past begin to emerge. What happened to Ivy, to her baby, and to the hundreds of children born in the home? What links a number of mysterious, sudden deaths in the area? And why are those who once worked at St Margaret's so keen that the truth should never be told? As Sam unpicks the sinister web of lies surrounding St Margaret's, she also looks deep within - to confront some unwelcome truths of her own.