Linda Hamilton, Zachary Levi

Now that Chuck (Zachary Levi) has "given up" being a spy, per Ellie's request, Chuck's Season 4 will focus on the hunt for Mama Bartowski—who will be played by Terminator star Linda Hamilton, it was announced at Saturday's Comic-Con That's not the only Bartowski coming to town either: Someone is pregnant! Get the very spoilery scoop below:

What is at the heart of the season? "It's all about family this season," executive producer Chris Fedak told TVGuide.com backstage. "The fun of the season is the search for mom. Chuck has this mission from his father: He has to find his mother. That is the heart of this season."

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Who is Chuck's mommy? "Linda Hamilton, [who will first appear in the premiere], is such an icon in terms of that action female, badass mom, and that really speaks to what we we're looking for," said Josh Schwartz on the panel, which kicked off with a performance from Jeffster."That's really going to be a huge part of the season. That's obviously a story that lands in Chuck's spy world and personal world." 

Will Chuck still have secrets? Though Ellie (Sarah Lancaster) asked Chuck to quit being a spy, the hunt for his mother will keep him in that world. "We go back to Chuck keeping a secret from Ellie when she's asking him to retire and be safe," said Lancaster. "So I look forward to that dynamic again this year."

Who has a mini-Awesome bun in the oven? "We're looking to expand our family," Lancaster revealed backstage of Ellie and Awesome (Ryan McPartlin). "There might be a little bun in the oven, which will be good because it will raise the stakes." Fedak confirmed the impending arrival of the baby who he said "will rule the world."

Who will replace The Ring? "We have a new big bad this year," Fedak said. "The big bad is a really important part of the story. Essentially we're going after one person the entire season, which is a little different than what we've done in the past."

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Who's taking over the Buy More? The Buy More is now owned and operated by the CIA, so every week there will be a new guest-star playing the role of Greta, "a CIA operative slash Buy More executive," said Schwartz. "Every week we will have a new Greta, and whether it's a woman or a man, the character's name is Greta." Olivia Munn will take on the role in the premiere, while Old Spice spokesman Isaiah Mustafah appears in Episode 2.

Will Chuck and Sarah's relationship survive? "Chuck and Sarah are a couple this year," said Schwartz. "We've learned about putting people in between Chuck and Sarah." Added Levi: "Even though we're together now, and we can be honest about being together and we're a couple officially, the love has always been there."