It's the end of an era. After 12 seasons,The Big Bang Theoryends Thursday night with a one-hour finale. Creator Chuck Lorre says "I'm grief-stricken that it ended, but at the same time, I'm proud of what we did. I'm grateful that we get to do it."
Here's the synopsis for the finale: "Sheldon and Amy await big news; Bernadette and Wolowitz leave their kids for the first time; Penny and Leonard try to keep a secret; Sheldon and Amy stick together; Koothrappali makes a new friend, the gang travels together into an uncharted future."
At 9:30 p.m. ET, ABC will air Unraveling the Mystery: A Big Bang Farewell,which will have starsJohnny GaleckiandKaley Cuoco looking back at the show, sharing backstage secrets, clips, personal memories and favorite moments. There will also be tours of the iconic sets.