In this Halloween episode Chuck meets a Federal agent just like him: A computer whiz whose brain is important to national security. However, Chuck soon has a personal dilemma arise when he has to decide whether or not to turn the man over to Sarah and Casey or to help him escape his handlers.

The episode begins with a flashback to the year 2004, where John Casey is involved with a female Russian named Ilsa, who claims she is a photo journalist. Later, in present day, Ilsa returns with a fiancé, named Victor Federov. Things get complicated when it is revealed that Ilsa is a French spy.

Efficiency expert Emmett Milbarge pays the Buy More a visit to inspect the branch, while a global terrorist looks for Jeff. Chuck needs to socialize with Jeff to find out about his connection to the terrorist. Finally, it all comes down to video games and the prevention of World War III.

A new mission has Chuck and Sarah posing as a married couple and interacting with some odd neighbors. The Buy More crew help Big Mike out after his wife files for divorce.

Chuck's life seems to be coming together, his long-absent father has returned and he landed his dream job. Unfortunately for Chuck, neither turns out to be quite what he expected.

Chuck must use his relationship with Awesome to protect a visiting dictator, Premier Goya, who is the target of an assassination. While Awesome is excited about the prospect of being a spy, Chuck is more concerned about Awesome and Ellie's safety.

Chuck and Hannah unexpectedly become part of agent Daniel Shaw's latest mission. Much to Sarah's chagrin, she gets paired with Shaw, who seems to be trying to get close to her. Meanwhile, Morgan and Ellie continue their mission to get to the bottom of Chuck's secretive and strange behavior.

Chuck and Sarah are assigned to train under Craig and Laura Turner, a married CIA team who, despite their impeccable record, hate one another. The Turners' stormy relationship forces Chuck and Sarah to wonder if they're doomed with the same fate. Meanwhile, Casey must train the newest member of the team Morgan.

Chuck and Sarah suspect Casey is carrying out private missions. Chuck fears the CIA's new operatives will render him obsolete. Morgan settles in with a new roommate. Awesome becomes uncomfortable with Ellie's research.

Chuck and Sarah put aside spy work to have a weekend of debauchery, but Awesome’s plans for Chuck’s big night don’t go quite as expected. Meanwhile, Ellie's investigation into her father's computer leads to a life-changing discovery.

As the team is tasked with finding one of the CIAs most wanted, Chuck fears that the Intersect may be going to Morgan's head. Meanwhile Sarah helps Casey navigate his relationship with Gertrude. Elsewhere, Captain Awesome makes a startling revelation about Jeff and Lester.

While Chuck and Sarah contemplate the next step for Carmichael Industries, Casey’s forbidden love, Gertrude Verbanski, walks back into his life with a questionable mission in South Beach. Meanwhile, Jeff’s enhanced intelligence leads he and Lester to suspect that something unusual may be happening at the Buy More.