Kyle and Bernard journey to New York City to steal the Citadel X Case from Manticore Headquarters before it's too late. Later, Kyle learns that a figure from his past is still alive and he risks everything to find them.

Citadel agents race to prevent Joana's assassination of President Aronov at the G8 Summit, where she plans to seize control of Russian satellites. The team must execute a dangerous infiltration mission and face impossible and deadly choices in a final confrontation.

As Joana accelerates the plan to assassinate the Russian President at the G8 Summit, Mason and Nadia take Abby to a safehouse in Scotland. But when they uncover the horrific truth about what was done to Abby, it triggers a devastating chain of events.

Mason and Dahlia set a high-stakes prisoner exchange in motion to negotiate for Abby's release. But as Mason's unraveling threatens to derail the plan, both sides race to execute the trade, leading to a shocking revelation from Abby that changes everything.

Abby's escape triggers deadly events as Mason fights Manticore assassins. Paulo and Joana advance their weapon while pursuing Mason. Bernard and Hutch race to reunite the group. After a violent clash with Nadia, Mason seeks help from an old enemy and uncovers Bernard's dark secret.

Nadia, Kyle and Carter are forced to work together to escape from Manticore and protect the X Case, but suspicion of one of our heroes reaches a boiling point, leading to an explosive reckoning.

After the shocking revelation of Abby's former identity, we learn of the past entanglements between Mason, Nadia and Celeste, and a horrific decision that reverberates still today. Meanwhile, Nadia and Kyle land at the Manticore compound in Morocco and risk their lives to free their fellow spy. But their hero's welcome is short-lived as they are forced to grapple with a dangerous accusation.

With one of their own being held hostage by Manticore, Kyle, Nadia and Carter risk everything to save them and thwart Manticore's plans to acquire nuclear weapons. As our heroes grapple with the nuclear threat, the identity of the mole within Citadel will be revealed, as will the awful truth that everything they know is a lie.