CBS has a big farewell planned for "The Big Bang Theory."

The network will air a half-hour retrospective special on the night that the series finale airs, Kaley Cuoco (Penny). They'll discuss their 12 years on the series and give viewers some new behind-the-scenes intel, including sharing memorable moments and leading a set tour.

The decided to move on; as one of the show's big three stars alongside Galecki and Cuoco, his planned exit prompted the end.

The final season has been bittersweet for fans, but it has had a lot of high points, of course. For example, "The Big Bang Theory" recently filmed its 276th episode, making it the longest-running multi-camera sitcom in TV history. We expect to celebrate that major milestone and others in the special.

"Unraveling the Mystery: A Big Bang Farewell" airs Thursday, May 16 at 9:30 p.m. ET/PT on CBS.

[via: Deadline]