Investigating the murders of three men stirs up trouble for DI Alex Graham, causing him to relive a past tragedy. Working with his old lover, DS Best, Graham must delve deep into the men's military histories to find answers. Having witnessed one murder, and now hiding out in a safe house, Liz Hunt gets word of the dead men, friends of her husband, Danny, who has isolated himself on the North York Moors to "think." What is Danny hiding? And is it disloyal to share her information with the detectives? But it's a sharply-winding path to catch this triple-killer, and DI Graham won't be resting until he can close this case, and the door to his terrible past.