Fresh off finally winning his first Emmy, comedy legend Bob Newhart has secured a second guest spot on CBS’ The Big Bang Theory. The episode, slated to air in November, will also feature Bill Nye the Science Guy.

CBS said that Newhart will be back to play Professor Proton, Sheldon Cooper’s (Jim Parsons) childhood idol. In the episode, Proton decides to ask Leonard (Johnny Galecki) for help with an experiment. Sheldon finds this insulting, so he calls up Proton’s main TV rival, Nye, who will play himself.

Newhart made his first appearance as Professor Proton last season and won an Emmy for the role. Even though he starred in one of the best remembered sitcoms of all time, the Bob Newhart Show star had never won an Emmy before.

As for Nye, the popular scientist recently appeared on ABC’s Dancing with the Stars. However, it was a short stay, since he was injured during last week’s performance show. He did try to perform this week, but earned low scores.

The special episode of The Big Bang Theory will air on Thursday, Nov. 7 at 8 p.m. The show’s current season kicked off last week.