Throughout its five-season run, one of Chuck‘s enduring mysteries has been the past of its female protagonist, Sarah Walker. This coming season, however, at least one Sarah-related mystery will be answered: Cheryl Ladd will play Sarah’s long-lost mother.

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The casting news comes from, which reports that Ladd will play Emma, Sarah’s mother, in at least one upcoming season 5 episode. The episode (the 8th in season 5) is scheduled to air in January and will be titled “Chuck vs. the Baby.”

Click here for more about “Chuck vs. the Baby” and other Chuck season 5 guest stars.

Cheryl Ladd is best known for playing Kris Munroe on the 1970s classic, Charlie’s Angels. Ladd joined the cast in 1977 when star Farah Fawcett left to pursue a movie career. Cheryl Ladd then remained on the series for 87 episodes, until its cancellation in 1981.

Ladd’s subsequent career has included an impressive number of TV movies and regular roles on short-lived series like Las Vegas and One West Waikiki. Her Chuck role seems to be coinciding with a career resurgence as a guest star: Cheryl Ladd appeared on CSI: Miami in 2009 and will play a love interest for Ducky (David McCallum) on NCIS later this season.

Related: Chuck season 5 premiere pushed to October 28.

Fans of Chuck will know that Sarah’s father, Jack Burton (played by Gary Cole), was a con man who regularly dragged his young daughter into trouble. After Jack’s arrest when Sarah (then known as Jenny) was in high school, the future-Sarah-Walker was recruited by the CIA.

While a grandmother was mentioned in season 4’s “Chuck vs. the Wedding Planner,” no mention of Sarah’s mother (or any other family) has surfaced before now. What events will bring about the return of this long-lost relative? How will Emma affect Sarah’s life?

We’ll find out in January.

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Is Cheryl Ladd a good choice to play Sarah’s mom? Who is your favorite Chuck season 5 guest star announced so far? Leave your comments below!

(Image courtesy of WENN)

Laurel Brown

Senior Writer, BuddyTV

Laurel grew up in Mamaroneck, NY, Grosse Pointe, MI and Bellevue WA. She then went on to live in places like Boston, Tucson, Houston, Wales, Tanzania, Prince Edward Island and New York City before heading back to Seattle. Ever since early childhood, when she became addicted to The Muppet Show, Laurel has watched far too much TV. Current favorites include ChuckModern FamilySupernaturalMad Men and Community. Laurel received a BA in Astrophysics (yes, that is possible) from Colgate University and a PhD in Middle Eastern Studies and History of Science from Columbia University before she realized that television is much better than studying.