Mrs Medlock is the dutiful housekeeper at Marwood Manor. One of the few remaining staff, she protects a dying aristocratic order, serving the Lord and Lady and caring for their sickly young son. For over the past twenty years, Mrs Medlock has become the keeper of secrets. Secrets of the family. Secrets of her own. Secrets that may be found in the manor's walled garden, out of sight but not forgotten. When a distant relative, Mary, arrives at the property in need of a place to live and with a determination to explore, Mrs Medlock fears the secrets of Marwood are no longer safe. And digging up the past may have deadly consequences for them all.