The mountain of Kinder Scout offers the most incredible views of the Peak District, but when thick fog descends there on a walking party led by enigmatic Darius Roth, this spectacular landscape is turned into a death trap that claims a life. For DI Ben Cooper however, something about the way Faith Matthew fell to her death suggests it was no accident, and he quickly discovers more than one of the hikers may have had reason to murder their companion. To make things worse, his old colleague DS Diane Fry finds herself at centre of an internal investigations storm that threatens to drag Cooper down with it.