Professor Proton AKA Arthur Jeffries will appear as a ghost to Sheldon Cooper one last time on The Big Bang Theory.
The character, who passed away in season seven, will make an appearance as a ghost once more in season twelve. TV Line confirms that Bob Newhart, who plays the late character, will be making his final appearance during the show's upcoming farewell season.
Professor Proton was a children's science show host, who became known to Leonard (Johnny Galecki) and Sheldon (Jim Parsons) when he was performing private science shows to people for money.
After forming a close relationship over the years, Arthur passed away at the end of season seven. He would later 'visit' Sheldon as a spirit, dressed in Star Wars Jedi robes.
Bob received his first Primetime Emmy Award for the role in 2013, taking out the award for Outstanding Guest Actor in a Comedy Series.
Last month, CBS confirmed The Big Bang Theory would be wrapping up after Season 12.
Chuck Lorre, the series creator, confirmed the news in a statement along with Warner Bros. Television and CBS.
"We are forever grateful to our fans for their support of The Big Bang Theory during the past twelve seasons," the statement reads.
"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."
The final season of The Big Bang Theory is set to air in 2019.