Following the stabbing of an officer on the base, Eliza warns Amy to get control of her investigation. Amy must find the traitor in the ranks of the Air Force. Kirsten, now working with MI5 partner Ramsay, uncovers key evidence linking a squadron member to the attack. With the force running out of leads on Chapman's killer, Kirsten follows a hunch. Amy takes a grave risk that puts her in jeopardy.
