Doctor Sheldon Cooper is about to go toe-to-toe with the one and only Doctor Emmet Brown in an upcoming episode of The Big Bang Theory. That's right, the hit CBS series is bringing in Back to the Future star Christopher Lloyd for a premium guest role. Though, his character is being kept a secret for the time being.

It isn't known if this upcoming episode of The Big Bang Theory Season 10 will tie into or crossover with any Back to the Future lore. CBS made the announcement Wednesday, confirming that Christopher Lloyd's episode would air on Thursday, December 1. Executive producers exclaimed that they were 'so excited' when making the announcement according to TVLine.

While Christopher Lloyd has had quite the illustrious movie career, he first became known for his iconic sitcom character Reverend Jim Ignatowski, playing that legendary role on Taxi from 1978 to 1983. He recently appeared on Syfy's 12 Monkeys and has been a guest star on quite a few popular shows, popping up in everything from Cheers to Chuck.

Related: New Big Bang Theory Trailer Teases the Final 10 Episodes

It sounds like time travel could be one of the elements at play in the upcoming story line. But the producers won't say outright. They do assure that audiences are going to love this special appearance. They had this to say.

"We think we've created a fun part that fans will really enjoy."

Christopher Lloyd is the second Taxi star to make his way to The Big Bang Theory in Season 10. Other Taxi alum Judd Hirsch was introduced as Leonard's father during the season 9 finale, and showed up for a big cliffhanger resolve in the Season 10 premiere, where it was revealed whether or not he slept with Sheldon's mother. It's possible that Christopher Lloyd and Judd Hirsch could be gearing up for a small screen Taxi reunion on Big Bang.

A more likely scenario will probably have Christopher Lloyd involved in Leonard, Sheldon and Howard's quantum gyroscope project, which has already called in the attention of the military, including Colonel Williams, a tough Air Force representative from the Air Force Materiel Command played by Breaking Bad star Dean Norris. It sounds like we could see Christopher Lloyd playing yet another scientist who helps the guys out. Or we could see Christopher Lloyd fully reprise his Doc Brown role in another Sheldon nightmare. Sheldon has already had a scene with The Flash this year, and he's traveled to the Star Wars universe in seasons past.

B. Alan Orange