In the pilot episode, computer nerd Chuck Bartowski (Zachary Levi) is drawn into shadowy global espionage when subliminal government secrets are downloaded into his brain. He soon attracts the attention of a CIA superspy (Yvonne Strahovski) and a hardened NSA agent (Adam Baldwin).
A top scientist attempts to remove all government secrets from Chuck's brain. But when the scientist is mysteriously killed, the NSA's Casey and the CIA's Sarah blame one another for the assassination---with Chuck caught in the middle of their battle. Elsewhere, Sarah goes undercover, working at a gourmet hot-dog joint to keep an eye on Chuck.
It's the revenge of the nerd when Chuck delves into his very first undercover spy mission: He tries to take down a mysterious, elusive arms dealer named La Ciudad. Elsewhere, in his real life, he sets out to become assistant store manager and also learns to dance the tango.
Sarah's fetching CIA colleague arrives, and Chuck joins forces with the two lady spies for a mission involving a million-dollar diamond and a terrorist-funding operation. Meanwhile, Morgan has eyes for Sarah's coworker; and Sarah's double life continues to perplex Chuck.
Chuck's value system as a spy is tested when he contemplates defying Sarah and Casey in a case involving an elite Chinese agent. Back at Buy More, Morgan's value system is also tested when he's thrust into a job-jeopardizing sales competition.
Despite being expelled from Stanford, Chuck returns to the school for homecoming to help a professor---who just happens to be a government operative. In the process, Chuck unearths deep secrets about his erstwhile pal Bryce Larkin. Meanwhile, Morgan squares off against Buy More's rookie assistant manager.
There's a surprise flourish to Chuck's love life when he connects with a fetching woman (Rachel Bilson) and squires Sarah on a date. On the espionage front, Chuck tangles with a poison virtuoso who's out to control nuclear facilities.
A surprising streak of jealousy is sparked in Sarah when Chuck begins dating a sandwichmaker named Lou (Rachel Bilson), a situation made more difficult when it's discovered that Lou may be involved in a smuggling ring. Meanwhile, a romance blossoms between Morgan and an unlikely woman.
It's Thanksgiving, and Chuck's day is stuffed with a big surprise: Bryce Larkin (Matthew Bomer), the agent who originally downloaded government secrets into Chuck's brain, returns in need of Chuck's help to prove he's not a rogue agent. Meanwhile, Morgan leads the charge to help Buy More prep for the busiest shopping day of the year.
Chuck poses as Sarah's husband to take down a counterfeiting yachtsman with strong political ties. Back at Buy More, the staffers take part in the store's annual holiday party, but the event comes with strict guidelines from Big Mike (Mark Christopher Lawrence).
When a contingent of Russian arms dealers descends upon Los Angeles for a clandestine meeting, Chuck discovers that one Russian lady may share a romantic past with Casey. Elsewhere, Captain Awesome and Ellie's romance hits a bump.
As Captain Awesome plans on popping the big question to Ellie, Chuck is delegated to guard the ring. But this lord of the ring gets into a tight spot when the band is pilfered. Meanwhile, the CIA inches closer to discovering the identity of "the intersect."