Sheldon will say goodbye to his beloved "Fun With Flags" web series in the next all-new episode of "The Big Bang Theory" this Thursday.

A preview of the upcoming episode, titled "The Champagne Reflection," reveals that Sheldon will record the final installment of "Sheldon Cooper Presents Fun with Flags."

"After only 232 episodes," says Amy in the video promo, before Sheldon jumps in to correct her, saying, "233 if we include the one that somebody forgot to press record on."

"You said you weren't going to bring that up," snaps Amy.

"And you said you were going to press record," Sheldon replies.

In the meantime, the geeky gang will have to deal with a move in the study and the death of fellow Professor Roger Abbot.

According to Star Watch Byline, CBS issued a synopsis for the episode, which states:

"Sheldon says a tearful goodbye to 'Fun with Flags.' Also, Leonard, Howard and Raj look for something significant in a dead professor's research, and Bernadette is shocked to learn her co-workers' true feelings from Penny."

On Nov. 11, "The Big Bang Theory" lost actress Carol Ann Susi, the woman who played Howard Wolowitz's mother, to cancer. The 62-year-old cast member was famous for playing the voice of Mrs. Wolowitz, which was a core part of the show, although she was never seen onscreen.

Kunal Nayyar, who plays Raj on the popular CBS comedy, talked about losing his co-star during a recent appearance on "The Ellen DeGeneres Show."

"Sadly, a couple of days ago, we lost one of our cast members," Nayyar told Ellen in an interview that aired on Monday, reports E! News. "She's famous because of her voice. She unfortunately lost her battle with cancer. We will miss her and she was a lovely lady. Her spirit will live with us on set forever."

Nayyar also revealed that he frequently gave her rides home.

"She's the only person I know in Los Angeles who didn't drive," Nayyar said. "For 30 years, she didn't drive a car. She would take the bus to work at 'Big Bang!'"

"The Big Bang Theory" Season 8, Episode 9, "The Champagne Reflection," will air on Thursday, Nov. 20 at 8 p.m. on CBS.

Watch a preview video below.

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