The characters who were introduced in the second and third season respectively will be back one more time in the middle of fourth season.
Nicole Richie's character on "Chuck" was working so well that the reality show star is tapped to make a comeback. EW reports Richie is going to reprise her role as Sarah's High School nemesis Heather Chandler in an episode airing in October.
Heather was last seen in the episode "Chuck Vs the Cougars" which aired in Fall 2008. Heather's nerdy husband Mark turns out to be a key player in a new mission and the agents must attend Sarah's high school reunion to prevent the sale of potentially dangerous super-bomber plans.
How Richie will return to the show, an insider informed EW, she "will resurface in October when a prison transfer goes awry and her character, Heather Chandler, ends up being stowed away at Castle" where the CIA is based. Not only that, Heather will also make use of a crack in Sarah and Chuck's relationship to her advantage.
Heather is not the only problem that the team faces in the particular episode. Stone Cold Steve Austin is also coming back as Hugo Panzer although his entrance story is still a question mark. He was last seen in the episode "Chuck Vs First Class" where he combats Chuck inside an airplane.
Interestingly, Austin's "The Expendables" co-star Dolph Lundgren is also guest starring in the series as a man who will "break" Chuck in the season premiere. Olivia Munn will accompany Lundgren in the September 20 episode.