AceShowbiz -

Jeffster found a way to top last year's performance at "Chuck" Comic Con panel, that is by going GaGa. The duo comprised of Vik Sahay's Lester and Scott Krinsky's Jeff took the audience at Ballroom 20 by storm by performing Lady GaGa's "Bad Romance" complete with the retro look. But instead of performing live and singing the song, Jeffster appeared in a featured clip.

Just when the audience thought it was the biggest treat of the day, they were given a recap of season three which ended with Linda Hamilton doing that turning-to-camera look she was famous for in "Terminator 2". The crowd cheered as the panel confirmed that the actress has been cast as Chuck's mom who will be a centric element of season 4. In the last season, Chuck and Ellie's dying father said that it is time for them to get to know who Elizabeth Bartowsky is.

"Forget Angelina Jolie when she was doing the Tomb Raider stuff," Ryan McPartlin aka Captain Awsome said. "Linda Hamilton was that. The sunglasses, the gun, the biceps. It's great!" Mom Bartwosky will appear as immediately as the season premiere but all will not be so sweet for she disappeared when Chuck and Ellie were kids. "She left, you know?" Sarah Lancaster aka Ellie said. "It's not the same sweetness as it was with Scott Bakula's character. It's going to be more like 'Who are you? Where did you go?'"

After a dark period in the third season with his father's death and Shaw's interference, Chuck may finally be happy with Sarah. "I have to say I was very excited to finally be part of the some of the happy stuff," Yvonne Strahovski aka Sarah announced. Also, Ellie and Awesome would expand their clan and have "little Awesomes."

"Chuck" returns Monday, September 20.