In the misty fells of England's Lake District, where ancient paths wind through deceptive terrain, DI Tobias Stone has returned to his childhood home after years with the Metropolitan Police, seeking quieter surroundings but finding deadly secrets instead.

What appears to be a tragic accident—experienced fell guide Michael Thompson found dead on Helvellyn—soon reveals inconsistencies that only someone intimate with the mountains would notice. When Stone discovers Thompson was about to report safety violations that threatened a rival's business, the investigation plunges into the close-knit fell walking community where outsiders are viewed with suspicion.

As storm clouds gather over the fells, Stone must navigate both treacherous mountain terrain and equally dangerous human relationships. His childhood knowledge of hidden paths and weather patterns proves as valuable as his metropolitan police training, especially when the killer attempts to use the landscape itself to escape justice.

The isolated valleys have shaped these people for generations, creating a pressure cooker of rivalries and resentments beneath the tourist-friendly surface. But in a place where locals read the fells like others read books, some truths cannot remain hidden.

Stone must reconnect with the community he left behind to catch a killer who knows the mountains almost as well as he does, before more lives are lost to the unforgiving landscape and the secrets it conceals.