Florist Persimmon 'Simmy' Brown is juggling life with a demanding newborn when visitors arrive in the Lake District with questions about a long-forgotten disappearance. Thea Slocombe and her brother Damien are searching for the truth about their great-grandfather, John Armstrong, who vanished without a trace in 1931, leaving behind his family and a medal awarded for an act of bravery few now remember. As dormant rumours of murder begin to surface, Simmy soon finds her investigative instincts reawakened.

With a resentful relative determined to prevent further enquiries, it becomes clear that some secrets have been buried for generations - and the trio soon find that history can be every bit as dangerous as the present.