Meet Chuck Bartowski. He's your run of the mill computer whiz working for Buy-More with his equally nerdy friends all while longing for the woman of his dreams. But Chuck's average life is suddenly turned upside down when an old friend, who happens to work for the CIA, sends Chuck a mysterious e-mail and the world's closely-kept spy secrets are embedded in Chuck's brain. Now Chuck has unwittingly become the government's most powerful weapon and the fate of both the country and the world now lie in his hands. A Buy More day job and saving the world are all in a day's work for Chuck.
Chuck is put under the protection of two rival intelligence operatives, Sarah Walker and Major John Casey. They're forced to work together and keep Chuck alive while taking him on assignments where his unique knowledge can prove useful on missions. Sarah has to stay close to Chuck by pretending to be his girlfriend. Meanwhile, Chuck has to keep his secrets from best friend and co-worker Morgan Grimes, and his concerned sister Ellie Bartowski.