Shemar Moore Is Returning to 'Criminal Minds' -- But Is He Staying for Good?

A familiar face is heading back to Criminal Minds!

Shemar Moore, who was an original cast member on the CBS crime drama, will return for the first time since leaving the long-running series last March after more than a decade.

But will the 46-year-old actor be staying on for good? Unfortunately for die-hard Derek Morgan fans, not at the moment.

RELATED: Shemar Moore Opens Up About 'Criminal Minds' Surprise Exit

Moore will reprise his role as FBI agent Derek Morgan, guest starring in the season 12 finale airing Wednesday, May 10, where Morgan will bring the BAU a lead in the case against serial killer and escaped convict Mr. Scratch, who has wreaked havoc on the team all season.

"BOOM," Moore wrote on Instagram. "My secret is out !!!! I'm excited to say.... Your Baby Boy will be back to play with my Criminal Minds family for the season 12 Finale!!"

Moore was a series regular on Criminal Minds from its inception in 2005 through 2016, when he left in the middle of the 11th season.

ET spoke with the actor last March about why he was bidding farewell to the show.

RELATED: 'Criminal Minds' Reveals What Happened to Thomas Gibson's Character

“I’m not leaving to go be a big star and try to make a lot of money,” Moore said at the time. “I mean, all that stuff is part of the business and part of the journey and the dream, [but] right now I’m just leaving to take a breath.”

Moore promised that his final episode “was not goodbye.”

“Derek didn’t die, so anything is possible,” he hinted, adding, "When I come back, I'm going to come back guns blazing and excited and ready to perform and dance and, hopefully, the fans will enjoy what I'm doing."

Criminal Minds has seen a few cast changes over the course of the 12th season, with series regular Thomas Gibsonabruptly exiting after a reported on-set altercation, the return of Paget Brewsterand the addition of new regularDamon Gupton.

Criminal Minds airs Wednesdays at 9 p.m. ET/PT on CBS.