Next month, Sheldon (Jim Parsons) will make a very important decision, with some help from a fan favorite. "The Big Bang Theory" is welcoming back Emmy winner Bob Newhart, who will reprise his role as Arthur Jeffries, or Professor Proton, in the Dec. 17 episode of the CBS show.

According to The Hollywood Reporter, Newhart will appear as a Jedi in Sheldon's dreams to help him sort out his feelings and make a very crucial decision. Could Arthur be giving Sheldon some advice about Amy (Mayim Bialik)?

This season, Sheldon has been coping with the aftermath of his breakup with Amy, which took place in the season 8 finale of the show. Amy broke up with him because she thought that their relationship was going nowhere, when in truth, Sheldon was getting ready to propose and had an engagement ring in his pocket. Recent episodes featured Sheldon attempting to win his girlfriend back, despite pleas from Amy for space.

The December 17 episode will mark Newhart's fourth appearance in "The Big Bang Theory." He made his debut in the hit comedy back in 2013's "The Proton Resurgence," which won him his very first Emmy award for his guest role. The actor was last seen in season 7 episode 22, where Sheldon learned that Professor Proton had passed away. That night, Arthur appeared to Sheldon in a dream dressed as Obi-Wan Kenobi, and he told Sheldon that it's alright to grieve for the ones who lost, but he should also some value those who are still around him. That episode was a tie in with May the Fourth, also known as Star Wars Day.

Speaking to THR in 2014, show runner Steve Molaro said that even though Newhart's character has passed away, he never really leaves the show because Arthur will live in Sheldon's conscience forever. And because of the way that he appears to Sheldon, Arthur will always be dressed as a Jedi Master.

Incidentally, Newhart's return to the CBS show takes place a day before the theatrical release of "Star Wars: The Force Awakens."

"The Big Bang Theory" airs Thursdays at 8 p.m. on CBS.