The threat from above is an ever-present danger ... A man falls to his death from a cliff face in western Scotland. From a distance, another man watches. He approaches the body, tucks a book into the dead man's pocket, and leaves. When the Scottish police contact Chief Inspector Domenic Jejeune and show him the book, he recognizes it instantly. He knows it's a call for help, but he also knows that answering that call would destroy the life he and his girlfriend Lindy have built together in England. It could also end his successful policing career. Or worse. Meanwhile, back in north Norfolk, a leading climate-change researcher has been brutally murdered. In Jejeune's absence, it falls to Sergeant Danny Maik to determine if the man's death was related to his controversial studies, or to the astronomical amount of prize money at stake in a contest the researcher was involved in.