Meanwhile, Michael and Sam pursue Anson Fullerton (Jere Burns) throughout Miami and corner him in a chemical plant, with eventual help from Agent Dani Pearce (Lauren Stamile).
Michael brutally attacks Anson upon finding him, but is forced to let him escape after learning that he wired the building to explode.
Sam is then kidnapped by former CIA operative-turned-traitor, Rebecca Lang (Kristanna Loken), so Michael and Jesse work to rescue him.
Both plans work, so Fiona becomes a CIA asset and Rebecca provides Michael with Anson's location where he's expecting his latest drop of travel documents and cash.
After Michael tells Fiona that they found Anson, he informs her that she has to plead guilty to a few weapons charges and her sentence will be time served.
At the same time, Sam and Jesse have to help Elsa's (Jennifer Taylor) son, Evan, who's gotten into trouble with a loan shark.
As Michael, Sam, and Fi take him down, Jesse and Pearce work together to find the gun used in the shooting by tracking down the company who made it.
After the team heads down to Panama, they meet with a CIA operative named Brady Pressman, who joins them in hunting Gray down.
While in Panama, Michael promises Fiona that after they capture Gray, he'll leave the CIA, which makes her happy since she misses the times when it was just them working together.
After learning that Gray was telling the truth, Michael grabs him and escapes with the team as an F18 air strike tries to kill them.
Although Jesse and Fiona help Michael escape, Sam is caught by Agent Olivia Riley (Sonja Sohn), a heavy-hitting CIA Officer who literally "wrote the book" on counterintelligence.
Sam and Jesse get passport chips from James Vanek (Kevin McNally), who wants revenge against Schmidt.
Schmidt tells Michael that their passports should be good but they shouldn't sit on them for too long in case Vanek gets caught.
Fiona doesn't want him to accept deals where he ends up in prison, so they get ready to leave the country the next day, only to find out the Union Rep set them up.
Sam claims that the bullet grazed him, but upon taking a CIA operative hostage and getting to safety, they discover that the gunshot wound is worse than he let on.
The team have Fiona's ex-boyfriend, John Campbell (Gary Weeks) patch Sam up without taking him to a hospital.
He refuses since he doesn't want to turn on his friends, so she tries a different approach and claims to have a file on his mother's killer, trying to emotionally manipulate him.
Riley pretends to surrender and offers to confess, but Michael realizes that she would've falsified records to make it look like he was working with the cartel.
After three weeks of being questioned about Riley and Card, Fiona is escorted out of her cell to see Michael outside, wearing a suit and giving orders to CIA officers.
[1] Jere Burns and Kristanna Loken returned to the series for multiple episodes as Anson Fullerton and Rebecca Lang, respectively.
[4] William Mapother appeared in the sixth episode as Garret Hartley, a mercenary hired to kill Barry (Paul Tei).
[5] Richard Burgi appeared in the seventh episode as a villain who has targeted Evan (Brando Eaton), the troubled son of Sam's new sugar momma, Elsa (played by Jennifer Taylor).
[6] Angélica Celaya guest starred in the ninth episode of the season as Angela Flores, a woman whose boyfriend is accused of illegally trading weapons on the black market.
[7] Chad Coleman appeared in the tenth episode as Brady Pressman, a CIA operative who, after failing in his mission to capture Anson alive, hopes to set things right.
[7] Also appearing in the tenth-to-twelfth episodes was Kenny Johnson as Tyler Gray, the trigger man behind the death of Michael's brother.
Oswalt appeared in episodes 14-16 as Calvin Schmidt, a smuggler whom the team contacts for help in escaping the country.
Sohn plays Olivia Riley, a high-level CIA director who "literally [wrote] the book on counter-intel training and procedures", and she appeared on a recurring basis beginning with the thirteenth episode.