Following a traumatic event in London, Kirsty Woodhouse packs up her family and moves back to her native Wales. There she sets up her new home with her husband and two young daughters and goes into business with her difficult mother managing a guesthouse in the Brecon Beacons. But when the guesthouse is ready to be occupied, Kirsty encounters the last person she ever expected to see: her estranged cousin Selena. It has been seventeen years since they last talked, when Selena tore everything apart between them. Why has she chosen now to walk back into Kirsty's life? Is Selena running from something too? Or is there an even darker reason for her visit? As Kirsty becomes increasingly concerned for the safety of her daughters, her dream home begins to feel like her worst nightmare. Kirsty knows that once trouble is invited in, it can be murder getting rid of it.