Jill, Chuck's college girlfriend makes an appearance. He bumps into her while fixing a computer at a convention. Jill is highly successful now with a doctorate in biochemistry, Jill's boss comes into the picture and he flashes on him who's involved with Bio-weapons, Chuck now has to get close to her to get some info. Chuck tells her how highly successful; he takes her to a fancy restaurant where they catch up on old times, when leaving he gets caught out by Lester and Jeff who tell her he still works in the Buy More.
Casey and many others are trapped inside a hotel where fatal bio weapon had been unleashed, Chuck has to save the day but needs Jill's help so he tells her he is a CIA agent and the Buy More job was part of his cover. His attempts to save the way led to some very funny situations where he had to use saliva to process the cure Jill had put within him, and kissed Casey. It's going to be interesting to see how Sarah's going to take the Chuck/Jill relationship in.