When a detective begins investigating a string of deaths by asphyxiation of former members of an elite sniper team deemed to be accidental, he eventually learns through his connection to the deceased that their deaths were methodically planned murders and that the serial killer's motivation is deeply rooted in his past as a master sniper in the Afghanistan war.
Long before Cyrus James Washington was a sergeant detective he obtained the exclusive rank of master sniper, which was a fraternity that included two dozen other sharpshooters in the entire Canadian Forces. During the Afghanistan war he led an elite sniper cell team that quickly became an all-star unit after they broke and re-broke the record for longest-ever combat kill, which raised the bar of their elite profession and earned them legendary status. However, as the tally of their body counts began to reach a level unmatched by any soldier in history, the ability to answer for every kill without an affliction of their moral conscience became impossible.
Thirteen years after the war the ex-snipers inexplicably begin dying one by one from different forms of asphyxiation in ways that first appear to be accidental. Cyrus, the lead investigator assigned to the accidental deaths, eventually learns that the deplorable actions of the ex-snipers during Operation Harpoon was forgotten by all except one person, who will not stop until all of them get their just deserts. As Cyrus confirms that his former brothers in arms are being methodically targeted, including himself, he realizes that one of the remaining victims is the serial killer. Once the third to the last ex-sniper is murdered by asphyxiation, Cyrus engages in a race against time to get to the serial killer first before he becomes the last victim.