Marcella Backland left the Metropolitan Police for the sake of her family, only to have her husband leave her. She returns to her job on the murder squad, investigating a case that seems disturbingly familiar to her.

When former detective Robert and his school teacher wife Katy decide to make major changes to their lifestyle, they impulsively purchase a guest house in the Lake District where they plan to create a haven for holidaymakers. When Mark, a former colleague and friend, approaches the couple asking for their help in providing temporary housing for people needing protection from criminals, their idyllic guest house quickly becomes a safe house.