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 orchestrate an intricate heist at a high-security bank. Elsewhere, Vivian is thrust into the spy world; Chuck and Sarah’s wedding plans heat up; and an unforeseen twist marks Morgan’s search for a new roomie.
Chuck and Sarah’s Valentine’s Day is put on hold when they must travel to England to protect an oil baron’s daughter. A mysterious woman makes Casey a compelling offer. Ellie and Devon receive parenting help from an unusual source.