A security guard at the Mallach oil terminal, on a remote Orkney island, goes missing. His family ask private investigator Danny Verity for help.
Danny takes a job at the terminal, whilst his partner, Gemma Gauld, searches the island. Her combative approach soon ruffles feathers and this seemingly tranquil community reveals some lethal hazards.
Meanwhile, Danny's new colleagues have secrets that they are desperate to keep from him and their employers. As he gets closer to the truth, the terminal becomes an ever more dangerous workplace.
When another local man disappears, the link between Gemma's discoveries and his own become clearer.
As the islanders and oil workers close ranks, Danny and Gemma are determined to uncover the truth. Facing a hostile community and a violent perpetrator, can they find out what happened to the missing men?