Cliff Lipson/CBS(NEW YORK) — After fifteen seasons, the crime drama Criminal Minds comes to a close tonight on CBS, with a two-hour series finale.  But don’t expect star Joe Mantegna to drop any plot spoilers ahead of the final broadcast, other than he feels fans will come away satisfied.

“You owe something to your audience if you have a show that’s been on 15 years,” Mantegna tells ABC Audio.  “It’s not something that’s going to be like earth-shattering, that’s far-fetched, but something that is probably very realistic.”

He adds: “The best, maybe if I had to put it in one sentence is: The beat goes on.  You know?”

Criminal Minds, set within the FBI’s Behavioral Analysis Unit, has undergone some significant cast changes over its 324 episodes.  Mantegna himself stepped in to replace original star Mandy Patinkin, who left the show after three seasons, while the only main cast members who’ve appeared in every season are Matthew Gray Gubler and Kirsten Vangsness.

But despite the turnover, Mantegna maintains the cast is “unbelievably tight. And you can’t create that. The chemistry either happens or it doesn’t happen.  I just feel so fortunate that it worked out that way. When we did that final episode not one of us would not have said, ‘Hey, let’s do fifteen more!'”

Mantegna’s also grateful that the show has allowed him to spend time with his family over the years, including the eldest of his two daughters, who has autism.

“From the time she was born we made that decision…to make things as normal as we can,” says Mantegna, noting that his family even traveled with him when the show shot on location.  “They went everywhere. …[W]e kept the family unit together.”

The Criminal Minds series finale airs tonight at 9:00 ET on CBS.

Copyright © 2020, ABC Audio. All rights reserved.