After a daring hijack spirals into a shadowy conspiracy, fearless MI6 agent Zara and ex-protection officer Vincent must confront ruthless mercenaries and their own harrowing pasts. While a deadly virus threatens to decimate Europe, Zara and Vincent are pushed to the edge. With countless lives hanging in the balance and the clock ticking, can they outwit the brutal mercenary leader Yuri Mishkin. Or will his insidious plan for chaos succeed?
The terrorist group Voltov kidnaps microbiologist Rachel Moss and forces her to create a deadly biological weapon. Zara and Vincent, who were monitoring Yuri Mishkin, the group's leader, must intervene to prevent the virus from being released and save Rachel.
Back in London, Zara realizes there's a mole within MI6. No longer knowing who to trust, she cuts off all official contact except with Karen, to whom she confides. In Benghazi, Rachel has to treat Vincent, who is seriously wounded. Vincent promises to help her escape if she saves him.
Zara warns Andrew, her superior, about a mole within MI6. But when he is murdered, Zara becomes the prime suspect. In Benghazi, Vincent and Rachel grow closer as they plan their escape.
Zara has found refuge with her former mentor, Keane. She is on the verge of unmasking the mole. In Benghazi, Vincent is infected with the MERS-CoV virus. Rachel is searching for a way to save him before the virus kills him.
Zara assembles a team of former mercenaries to capture Voltov. Vincent, who has managed to escape, finds refuge with Hassan, an interpreter he met on a previous mission. Yuri sets in motion the most devastating phase of his plan.
Keane, held back by Yuri, refuses to betray Zara. Meanwhile, with Hassan's help, Zara and Vincent attempt to infiltrate Voltov's base to rescue Rachel and the other hostages of the organization.
Zara and Vincent travel to Spain to find Rachel's family. Yuri is about to carry out his plan, but an unreliable source leaks it to Zara and Vincent, who are unsure whether to believe it.
