Vigil

When a British Air Force weapons test goes disastrously wrong, DCI Amy Silva is called in to investigate. With seven military personnel dead, two from Britain's allies in the Middle East, Amy finds herself caught in the crosshairs of a fraught international incident. The Air Force think they have the guilty party in custody and push for Amy and DI Kirsten Longacre to close the case. But Amy isn't convinced.

Amy and Kirsten are battling for their lives against a ruthless armed killer. They manage to escape. Following new evidence, the case takes a turn. Amy must go to the Air Force base in the Middle East. There, she learns someone on the base was complicit in the attack. Meanwhile, in Scotland, Kirsten hunts down Chapman's killer, determined not to let her pregnancy get in the way of her mission.

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.

Amy and Eliza come face to face with the dissident group at the heart of the investigation, and are held hostage. What's worse, they are told they have to help a member of the group infiltrate the base. Desperate to find Amy, Kirsten will go to any length, even if it breaks her own moral code, to track her down. Meanwhile, Amy and Eliza have no choice but to find a way to escape, despite the risks.

In the aftermath of a brutal rescue mission Amy is questioning everything. She is convinced that what she's believed up until now has been a lie, but all the evidence points the other way. With Amy completely isolated, Kirsten begs her to come home, but Amy can't let go of her suspicions. Despite huge pressure from above, Amy refuses to leave Wudyan, putting herself in grave danger.

With one person dead, and another injured on board, as Amy flies home, she is left scrambling for answers. Running out of options, Kirsten agrees to meet with Sutherland, putting herself in even greater danger. When Amy discovers the full scale of the conspiracy, she must decide if she is prepared to risk everything to find those responsible.