Paget Brewster, Criminal Minds

The news that Paget Brewster will return to the cast of Criminal Minds in Season 7 gave many fans reason to cheer. But executive producer Erica Messer's reaction was more a sigh of a relief.

Paget Brewster returns to Criminal Minds; Rachel Nichols to exit

And for good reason. Messer, who will officially handle showrunner duties this season, is coming off a Season 6 that was rocked by the never-fully-explained cutting of two fan favorites, Brewster and A.J. Cook, from the cast. But with both women now back on board, Messer says she's excited to move forward.

"It feels rewarding," she tells TVGuide.com exclusively. "This team works well together and now we can get on with telling the stories that have kept us going for six seasons. 

But the good news for Brewster means bad news for Rachel Nichols, who will not return full time next season after recurring this past year. Below, Messer discusses that painful decision process, how the return of Brewster's presumed-dead character, Emily Prentiss, will affect the team, and the power of the Criminal Minds fans.

Photo Gallery: See more TV characters we want back on their shows

TVGuide.com: What are your plans for reintroducing Prentiss to the team?
Erica Messer: This will be the first order of business on Tuesday. The writers will be back and we will officially dive into Season 7.

TVGuide.com: Will she have changed any since we last saw her?
Messer:
  Absolutely. No one goes into hiding and comes out unscathed. She has been in defensive mode for months now. She'll be exhausted and will have to face the family to explain a few things.

TVGuide.com: Starting with the fact that she's alive! What will the team reaction be, given that many of them believe her to be dead?
Messer:
There will be a lot of tension. Hotch [Thomas Gibson] and JJ [Cook] kept a big secret from the team. Ultimately. those kept in the dark will forgive the others when they find out Prentiss is alive.

A.J. Cook to return to Criminal Minds

TVGuide.com: What can you say about letting Rachel Nichols go?
Messer: It wasn't an easy decision and it took a village to make it. Having eight characters on Criminal Minds seemed unlikely.  Rachel is a real trouper and a pro. She walked into an incredibly difficult position and handled it with grace. The cast felt she fit in — we're actually a funny group off-camera — and she will be missed by all of us who worked with her everyday.

TVGuide.com: Will she appear in any capacity to wrap up her character's story?
Messer:
As storytellers we hate leaving threads undone. Creatively, there's more to explore there. I won't know for a bit if that's a possibility.

Check out photos of the Criminal Minds cast

TVGuide.com: What's the latest on Thomas Gibson's contract?
Messer:
[He's in] ongoing negotiations that I hope close soon. I have visions of the premiere in my head, but would feel better knowing he's back.

TVGuide.com: So, do you have a theme for next season at this point?
Messer:
Our theme hasn't been discussed yet, though right now it seems like surprises await all of us, on-screen and off. So maybe there's something in that.

TVGuide.com: Looking back at last season overall, how did the cast changes detract from the original goals?
Messer:
The cast issues gave us unexpected story lines, and I think we handled that the best we could. The goals for the season were altered, but the theme of secrets had been set and our Prentiss storyline reflected that in every possible way — before, during and after her battle with Ian Doyle [Timothy V. Murphy].

TVGuide.com: Do you want to do come back bigger and bolder than ever this year?
Messer: Having the band back together is in itself a huge victory and should give everyone a sense of security. Once that's established, we can get our heroes back to solving twisted tales.

TVGuide.com: How much did the fan outcry play into bringing back A.J. and Paget?
Messer:
Our fans are some of the most loyal I've ever known. And they're not shy. Their love for our show and investment in the characters is beyond encouraging. If their enthusiasm helped everyone see how important the unity of our team is, fantastic.