We finally know where Beth's (Susan Kelechi Watson) feisty spirit comes from on This Is Us; sitcom legend Phylicia Rashad is joining the NBC drama as Beth's mom later this season, TV Guide has learned.

Rashad will guest star as Carol in a highly anticipated episode later this season that will reveal Beth's backstory. The show has already teased that Beth's upbringing was not as rosy as one would expect, and you know the producers didn't bring in a heavyweight like Rashad just to hang around and be cool. It is going to be amazing to see Watson and Rashad go toe-to-toe. Get the tissues ready, friends.

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Rashad is, of course, best known for her role as Clair Huxtable on The Cosby Show. She currently has a recurring guest role on Empire and most recently reprised her role as Mary Anne Creed, the mother of Adonis (Michael B. Jordan), in Creed II.

As for This Is Us, the Beth-centric episode comes after the show revealed that there's another big question surrounding the Pearson family: How did Jack (Milo Ventimiglia) survive Vietnam? That mystery was added to the list along with "Who is the 'her' future Randall (Sterling K. Brown) and Tess are going to visit?" There are a lot of things that need to be answered before the show wraps its third season this spring.

Entertainment Weekly first reported the news.

This Is Us returns Tuesday, Jan. 15 at 9/8c on NBC.

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