‘Big Bang Theory’: Bob Newhart Set to Return for Final Season

Comedy legend Bob Newhart will make one last appearance on The Big Bang Theory during the long-running CBS sitcom’s final season.

A representative for the show confirmed the news to TVLine, but did not offer further details other than it will air before the end of the year. Based on Newhart’s past appearances though, he will likely show up as the ghost of Arthur Jeffries/Professor Proton to offer Sheldon Cooper (Jim Parsons) some sage advice.

This will be Newhart’s sixth appearance on the show. Professor Proton died in the season seven episode “The Proton Transmogrification,” but he has continued to reluctantly appear in Sheldon’s dreams. His most recent appearance came in November’s “The Proton Regeneration,” in which he helped Sheldon come to terms with Wil Wheaton being cast as the new Professor Proton.

Executive producer Steve Holland previously told TVLine that Newhart was one of the Big Bang guests they wanted to to “see again” before the show ends.

CBS previously announced that Keith Carradine will also return to the series as Penny’s (Kaley Cuoco) father, Wyatt. This will be Carradine’s fourth appearance on the show and first since the season 10 episode “The Conjugal Conjecture.”

CBS and Warner Bros. TV surprisingly announced that The Big Bang Theory‘s 12th season will be its last in August. The decision came while the studio and network were in talks to renew the show, but Jim Parsons told the cast and crew he did not want to sign on for a 13th season. Rather than continue the show without Parsons, all parties agreed to end the show instead.

“We are forever grateful to our fans for their support of The Big Bang Theory during the past twelve seasons,” Chuck Lorre Productions and WBTV said in a statement. “We, along with the cast, writers and crew, are extremely appreciative of the show’s success and aim to deliver a final season, and series finale, that will bring The Big Bang Theory to an epic creative close.”

Parsons also issued a statement, thanking fans for their support and expressing how thankful he was for the show that changed his life.

The season premiere episode is titled “The Conjugal Configuration,” and finds Sheldon and Amy (Mayim Bialik) on their honeymoon, while Penny and Leonard (Johnny Galecki) begin to realize they have a lot in common with Amy’s parents (guest stars Kathy Bates and Teller). Raj (Kunal Nayyar) also gets into a Twitter battle with Neil DeGrasse Tyson.

The Big Bang Theory returns on CBS at 8 p.m. ET on Monday, Sept. 24. The series then moves to Thursdays on Sept. 27 at 8 p.m. ET for the rest of the season.

Photo credit: Michael Yarish/Warner Bros. ©2013 Warner Bros. Television/CBS