As the nation celebrates the rescue of a captured Marine, a CIA operative receives a tip that the rescued Marine has actually been turned against his country, but she faces an uphill battle to convince anyone that the celebrated war hero is actually a turncoat.
As Brody struggles with the trauma of his long years of captivity, Saul tries to get their surveillance of Brody legalized. Carrie gets some intel about Abu Nazi's dealings with a Saudi prince.
Carrie suffers a crushing blow after her desperation to get a lead on Abu Nazir ends in a tragedy. Conflict brews in the Brody family as the media attention brings their problems to the forefront.
With Carrie coming up empty with evidence against Brody, her frustrations mount as the aftermath of Lynne's death and the pursuit of her stolen necklace yield no results as well. Brody is confronted about his erratic behavior as tension mounts between him and Jessica.
Carrie struggles with her mental illness as her attempts to get a lead on Abu Nazir or prove Brody's treason continue to prove futile. Brody comes face-to-face with one of his captors with unexpected results.
Carrie comes up with a way to discern the truth about Brody, but ends up compromising herself in the process. Brody confronts what he did to Tom Walker during the latter's funeral.
The CIA catches a break when they manage to arrest Aileen. The Brody family addresses the issue of Mike and Jessica's affair. Brody and Carrie grow closer, but a slip up causes some shocking revelations to come to the surface.
With the news that Tom Walker is alive, the CIA scrambles to locate him as the news sends Brody in a tailspin. Elizabeth Gaines makes a tempting offer to Brody.
Brody reflects on the reason he turned on the US government. Carrie faces a dilemma when her only shot at getting information on Tom Walker means getting the FBI to admit to gunning down innocents unprovoked.
Saul and Carrie look for dirt to use against the Saudi diplomat involved in the terrorist plot. Brody prepares to run for congress.
Saul finds out about Carrie's bipolar disorder, but her manic episode leads to a revelation about Abu Nazir's activity. Brody meets a contact in Gettysburg in preparation for their upcoming operation.
The target of Brody's attack is revealed. Carrie's attempt to prevent the attack is hindered by Saul's distrust of her mental stability and her feelings for Brody.