When a weapons test turns deadly, with allies from the Middle East among the dead, all eyes are on DCI Amy Silva, who tries to ignore the politics to get to the truth.
After escaping from a gunman with her life, Amy follows a new lead to the Middle East. There, she learns someone on the airbase was complicit in the attack. Meanwhile, in Scotland, Kirsten hunts down Chapman's killer.
When an officer is stabbed on base, Eliza warns Amy to get control of her investigation. Meanwhile Kirsten uncovers key evidence linking a squadron member to the attack.
Amy and Eliza are held hostage by the dissidents at the heart of the investigation, who demand their help to infiltrate the base. Kirsten will do anything to find Amy.
