After four months of being "dark," Agent Annie Walker emerges from the shadows to rejoin the DPD. A terrorist threat thrusts Annie back into the field, where she encounters a man named Ryan McQuaid.

Annie goes to Venezuela to find the terrorist involved in the Chicago bombing who got away, but discovers that McQuaid is already there with the same objective.

Annie and McQuaid are stuck in Venezuela after their effort to cross the border into Columbia with Borz fails, but it gives Annie enough time to get some answers about Borz's terrorist operation.

While investigating a lead in the Chicago bombing, Annie has an accident that could reveal her heart condition to the agency and cost her her job.

Auggie turns to an old flame, Natasha, to hack a Paris bank and find out who funded the Chicago bombing. Meanwhile, Arthur has a busy day in the field and Joan asks Calder to help get the heat off of them.

Annie risks her identity to reconnect with the Russian banker who financed the bombing, but McQuaid comes to her aid. Meanwhile, Auggie is forced to juggle two relationships, and Calder finds a familiar face in the internal investigation.

Annie and McQuaid go to Azerbaijan to find an ex-CIA employee connected to the bombing, Auggie's relationship with Natasha is in jeopardy, and Calder's call-girl acquaintance is in trouble with the law.

Annie is assigned to desk duty after Joan and Calder find out about her heart condition, but she still goes behind the agency's back with McQuaid's help to investigate a new lead in the bombing.

After Annie decides to leave the agency and work for McQuaid, she discovers a possible link between McQuaid and the Chicago bombing. Meanwhile, discovers that Auggie covered up Annie's heart condition.

McQuaid is on the run, and Annie risks everything and comes to his help after he claims that somebody has set him up and he is not responsible for the Chicago bombing.

As McQuaid's health hangs in the balance, Annie heads on a reconnaissance mission in Istanbul. Meanwhile, Arthur takes the reigns at McQuaid Security and Calder recruits a new asset.

Annie heads to Germany in search of a rogue chemist after Auggie uncovers a startling link between the recent attacks on American soil.

Reinvigorated by a shocking revelation, Annie works with a new ally to bring Belenko's misdeeds to light. McQuaid and Joan head into the field while Calder enlists Sydney to make a dangerous gamble.

With no options left, Annie and McQuaid must sneak into Russian territory to hunt down Belenko. Unanswered questions surrounding Auggie's past lead to a chilling confrontation.

Annie and McQuaid's relationship deepens as they track down Belenko's next target in Buenos Aires. Joan determines that it's in the CIA's best interest to keep Belenko alive.

With Russian Vega Force assassins hot on their trail, Annie and McQuaid work together to escape Argentina. Belenko's final plan is put into action.