Criminal Minds

On Wednesday's episode of Criminal Minds, the members of Behavioral Analysis Unit — and viewers — will say goodbye to Agent Jennifer Jareau.

JJ's exit comes after CBS abruptly let A.J. Cook go for creative reasons during the break between seasons.

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"It is like losing a member of the family very suddenly and without any warning. That's always difficult," castmate Thomas Gibson tells TVGuide.com. "Everybody is still mystified and always will be as to the reasons for this. I don't understand it, and I'll never pretend to understand why they had to do it. But it's a huge loss and there's now a void there."

JJ's exit will come as she and the team tries to reunite a family whose daughter has mysteriously disappeared. "We've always intimated that JJ's character has connections outside of our world — other more powerful elements in the government," executive producer Simon Mirren tells us. "Those powers that she's connected with come back into her life. So basically, what we're saying is, our loss is going to be someone else's gain.

"You see how the characters are in control of the cases and the people they go after," Mirren adds. "But outside of that, they realize that the FBI and the powers that be are more powerful than they are."

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With JJ seemingly on to bigger and better things, the focus will be on how the team reacts to being a man down. "Quite often after any show loses a big star, you see a spike [in interest] after their exit because the fans want to know how the family will cope with that loss," Mirren says. "So that's our main focus at the moment: to deal with that loss and how our main characters react to it. You get a lot of story from that, and your hand is sort of forced to see those characters' lives more."

Gibson says the real-life emotion surrounding Cook's exit will be mirrored on the show. "It was an interesting challenge and an interesting show to shoot," he says. "We're just trying to keep the ball in the air ourselves. We tried to integrate a little bit of what was happening in reality into the show. We didn't try to neatly wrap up something that we didn't feel could be neatly wrapped up."

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And while the plan is ultimately to bring in a new team member, don't look for it anytime soon. "The team has a choice to replace her or not. That's one of the surprises that people don't know about," Mirren says. "Our family has lost a member, and they're irreplaceable. But also somebody has to do that job [as communications liaison]."

"Even if they were to bring somebody else on in the future, the space left by her character is obviously never going to be filled," Gibson adds. "We miss her a lot, and we were lucky to have the time with her when we did."

Criminal Mind airs Wednesdays at 9/8c on CBS.