(CBS) "Glee" stars Lea Michele, Chris Colfer and Cory Monteith will not be back for the show's fourth season.
Show creator Ryan Murphy said in an interview that the three regulars will be among the characters who graduate at the end of the third season, which premieres this fall.
Murphy told The Hollywood Reporter: "You can keep them on the show for six years and people will criticize you for not being realistic, or you can be really true to life and say when they started the show they were very clearly sophomores and they should graduate at the end of their senior year."
"We've never done anything by the book," he added. "We made that decision and I involved Chris and Lea and they thought that was a good idea. They both trust the writing and trust me and felt that it would be great to have an open and closed experience for them to go out while they were on top."
Planning beyond high school will be one of the season's themes, Murphy noted, and "more characters are leaving than are staying" when it comes time for graduation.
Which characters are graduating and which characters are staying will be revealed during the Sept. 20 premiere, the creator told THR.
"We always knew we'd graduate in real time. It's all part of the plan and it's all good! It's going to make Season 3 amazing!!!" Michele wrote on her Twitter account on Wednesday. "To Gleeks everywhere, you're in my heart now and forever. Love u all!!! This is just the beginning!!"