Michael must work with an enemy to keep chemical weapons out of the wrong hands.

The CIA abandons Sam after he goes undercover with a heroin dealer while trying to recover a weapon. Meanwhile, Pearce continues searching for Max's killer.

A friend of Jesse asks the team to help take out his boss, who has been smuggling blood diamonds into the country with the help of diplomatic immunity. Michael asks Pearce for help transferring a prisoner who may be able to provide him with information on Anson.

The CIA recruits Fiona to break into a guarded safe after a civilian asset winds up in over her head. Meanwhile, Sam and Jesse visit a mercenary training camp to track the sniper who killed Nate.

Michael and Fiona pose as hackers at a malicious programming syndicate in order to steal information for Sonya. But Michael’s life gets complicated when working with Fiona again brings back painful memories. Meanwhile, Sam and Jesse help Barry track down a former girlfriend in exchange for falsified documents.