Life in espionage takes its toll on Chuck and everyone is taking notice. Chuck tries to explain his unusual behavior to Ellie and to the quirky Buy More efficiency expert Emmett Milbarge, but a new assignment only complicates things. After a global terrorist comes searching for Jeff, Chuck is forced to socialize with Jeff in order to find out what role the oddball plays in the mission. Sarah, Casey and Chuck are all shocked when they discover that the fate of the world and the prevention of World War III rest in Jeff's hands.

Chuck and Jill are enjoying the honeymoon stage of their rekindled relationship. The two lovebirds plan a weekend getaway but have to cancel at the last minute when Casey and Sarah inform Chuck that he is needed for an immediate mission to find corrupt agents in the CIA. Jealousy erupts when Jill finally meets Sarah and learns that Chuck and his handler must pose as a couple. Chuck does his best to reassure Jill that his relationship with Sarah is purely business but only finds himself in more trouble when his mission does not go as planned. Meanwhile, corporate efficiency expert Emmett is out to get Chuck and interrogates Morgan to get some dirt on his best friend.