(S02E04) A high school reunion episode? Didn't I see this before? Well, yes, the idea of a plot centered around a high school reunion has been a popular staple on episodic TV, but the way Chuck used the concept was really something special.

It gave us new insights into Sarah's character and deepened her connection to Chuck. There was still plenty of action, but oh how I love that back story.

Guest star Nicole Richie -- looking pretty, but in need of a milkshake or two to put some meat on her bones -- is not much of an actress. Still, she can play a jealous skank with aplomb, and that was her role here.

As Heather Chandler, Sarah's former classmate at San Diego's James Buchanan High, Chuck discovered things about Sarah heretofore unknown. Good for us viewers, too. If you haven't watched the show yet, beware plot revelations after the jump.