The latest case has definitely lit a fire in JJ (pun intended).

Wednesday's episode of Criminal Minds finds the BAU hunting a pyromaniac unsub, and the case really shakes up — and emboldens — JJ (A.J. Cook) after the abduction of two children.

"I can't imagine what would drive a parent to do something like this," JJ says in our exclusive sneak peek, as she, Reid (Matthew Gray Gubler) and Alvez (Adam Rodriguez) survey a burned-down house.

"The team suffers a loss in this one and she comes home definitely affected by it. Her kid is sick and it's sort of that feeling of you can't control any of it," showrunner Erica Messer tells of the episode, which will feature the return of Cook's real-life sons, Mekhai and Phoenix Andersen, as her TV sons, Henry and Michael. "You did the job as best you could and you don't think you won the day. And you come home and your kid is sick and there's not much you can do about it."

Criminal Minds Season 12: Everything you need to know

JJ will end up working closely with newbie Alvez on the case, which will lead to a "moment of bonding," Rodriguez teases. "He gets to work right away with JJ. They end up getting into a pretty hairy situation early on," he says. "There's a moment of bonding there. He does end up helping her out of a pretty dangerous situation."

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

(Full disclosure: is owned by CBS.)