Off the Libyan coast, Russian terrorist group Voltov kidnaps microbiologist Dr. Rachel Moss and forces her to make the MERS virus deadlier and more contagious. As MI6 agent Zara Taylor monitors Voltov with PMCs, an attack leaves her friend Vincent Taleb fighting for his life.

Back in London, Zara discovers a mole within MI6 after her car is attacked. Going off-grid, she suspects her superior and Karen’s husband, Andrew, are behind the leak. Meanwhile, at Voltov’s Benghazi base, Rachel saves an injured Vincent, who promises to help her escape in return.

After warning Andrew about an MI6 mole, Zara finds him murdered and becomes the prime suspect. In Benghazi, Vincent and Rachel’s escape plan fails, bringing Yuri’s brutal revenge. Zara uncovers Voltov’s plan to develop a biological weapon and goes on the run. Hiding with her former mentor Keane, she faces another deadly attack as she races to stop Voltov.

Zara and Keane escape Voltov’s mercenaries and use their vehicle to track down a crucial lead. In Benghazi, Yuri infects Vincent with MERS, leaving him hours to live. Back in London, Zara and Keane expose the MI6 mole through Voltov hitman Lennon. As Zara confronts the traitor, Rachel races to find a way to save Vincent before it’s too late.

Yuri kidnaps Rachel’s children, forcing her back under his control. Meanwhile, Vincent escapes the Voltov base and seeks refuge with Hassan, but mercenaries soon find him. In Benghazi, Zara discovers Vincent is alive, only for her PMC team to be captured. As Zara and Vincent plan a rescue, Karen meets Rachel’s colleague Marcos in Madrid and takes a suspicious interest in his MERS research.