Another person close to Joe is found dead. Bob shares his theory about the IEP attack with Sharla. Iris gives Mae information that puts both of their lives in jeopardy.

Joe's morality is put to the ultimate test as he attempts to stop the plague from being released.

Reuel and Marty hope that Caleb Woolf will be the key to Joe's capture. Bob attempts to extract information from Joubert. In Riyadh, a plan is put into motion.

Deacon's traumatic past comes into focus. Sharla pursues Joubert. Mae makes a terrifying discovery. After the location of the plot is uncovered, Bob considers his options and Joe compels Janice and Caleb to help him.

CIA analyst Joe Turner finds a clue that sheds new light on a failed biological attack at a US football stadium. The evidence threatens Joe’s life along with everyone he cares about.

Mae is tortured by lingering questions surrounding her husband's death. Caleb tells Joe about his CIA source. Joubert and Boyd cross paths at Kathy's house and make a critical discovery.

Joe is lured back into the danger zone when he suspects that Bob's killer and mole may be the same person.

Joe is travelling in Europe when he is approached by a Russian agent, who says he can identify a mole within the CIA in exchange for protection. Joe begins to realise that escaping his old life may be impossible.

Joe makes a new discovery in the hunt for the mole. At the same time, he realizes that he is not alone in monitoring a potential lead.

News of the massacre at IEP spreads. Bob seeks an ally after learning that he must remove himself from the operation to find Joe. Reuel questions Mae's knowledge of Sam's recent behavior.

Joe continues piecing evidence together. Bob deploys a capture mission without Reuel's approval. Mae receives intel from Iris about Sam and Elden. Nathan confronts Gareth.

Reuel gets a nightly visit and realizes that he ended up in the middle of an unexpected conflict. Kat defies her own judgment when helping an old friend.

Joe escapes Joubert and Deacon and calls Bob Partridge to bring him in. Sam Barber wrestles with his betrayal of Joe, which causes his partners to doubt his loyalty.

With the task force closing in, Joe is forced to flee with Kathy. Marty suspects there may be a mole on her team. Reuel grows increasingly concerned about Bob's loyalty. Joe's search for answers leads him to two important people from his past.

Joe is skeptical that Gordon is guilty and continues to look at alternative theories. Eva and Gordon unleash together and dig down the battle ax after a successful event.

Tracy and Mae decide to disappear for a while. Joe has finally learned of Vasili's whereabouts and is aiming for a reunion.

Joe continues to follow the evidence and makes a new discovery that intensifies his attempts to find Vasili.

Kat witnesses when Volk takes the law into his own hands. Mae's discussions with Senator Thrush have unintended consequences.

Life changes forever when things do not go as Joe planned. Kat has to choose side.

Joe runs out of options and is forced to put his loved ones at great risk. Mae makes tough demands on Reuel.