Things will get intense during Wednesday's all-new episode of "Criminal Minds" as the BAU tracks down a killer with an affinity for medical experiments.

A preview of the upcoming episode, titled "Future Perfect," shows a woman lying on a stretcher being pushed into what appears to be an operating room. Once she's in the room, she turns to the left and sees a man who seems to be strapped down to a gurney as well. Meanwhile, both of their mouths are tied.

According to CarterMatt, CBS released a short synopsis about the midseason finale, which states: "The BAU searches for an UnSub who may be fascinated with medical experimentation."

New spoilers also reveal that "Grumpy Cat" actress Aubrey Plaza will make a guest appearance as Dr. Spencer Reid's (Matthew Gray Gubler) love interest once the police procedural drama returns next year. TVLine reports that Plaza will play a woman named Cat Adams who erratically pulls a gun on Reid while they are on a dinner date. Reid's date from hell transforms into a game of wits when Cat discloses that she knows that he works for the FBI and then tasks him to think on his feet to save himself and the other people in the restaurant. The "Parks and Recreation" alum will guest-star in the Season 11 midseason premiere on Jan. 13.

Later in the season, Rossi (Joe Mantegna) may also get another shot at love when he reunites with his second ex-wife. Although he has vowed to never remarry after his three divorces, it appears that he might have a change of heart when he reconnects with Hayden (Paulette Ivory), the mother of his daughter Joy (Amber Stevens).

"We're talking about, since Joy is in the picture, her mom being in the picture again as well," executive producer Erica Messer teased, reports TV Guide. "We haven't ironed all of that out yet ... but that's been a point of discussion that we've had. That might be a nice thing for Rossi to find later in life, to actually find that happiness that he was looking for so much when he was younger."

Episode 10 of Season 11 of "Criminal Minds" will premiere on Wednesday, Dec. 9 at 9 p.m. ET on CBS.

Watch a preview video below.