'Criminal Minds' Showrunner Teases Season 13 Finale Cliffhanger as 'Surprising'

The season 13 finale of Criminal Minds is almost here, and the showrunner says fans can expect a "surprising" cliffhanger.

Erica Messer, who has been with the show since 2005, recently opened up to Entertainment Tonight and spoke about a few details of the back-to-back episodes that close out the current season.

"We are going to take you into two totally different worlds [in the finale]: one in Taos, New Mexico, about a real phenomenon called The Hum, which is an amazing thing that exists all over the world and it's up for debate whether people believe in it or the power of it," Messer said about the first hour-long episode that will air. "It felt like an interesting opportunity for the team to discover this."

For the second episode of the night, and the official season finale, Messer promises a "surprising" cliffhanger that culminates after Reid (Matthew Gray Gubler) discovers Violent Criminal Apprehension Program agent Owen Quinn (guest star James Urbaniak) in a storage unit.

"A colleague who has been missing for a year has been held captive and tortured," Messer teased. "While Dr. Reid was missing [last year], this other agent went missing, which is why none of us knew about it."

"It is interesting to think one of our own could've been a victim for this long, and then the question becomes: Was he truly a victim this whole time? Or has he lost his mind? It's an interesting journey to take with Dr. Reid and Agent Quinn being at the center of the investigation," she then added.

Messner goes on to explain that Quinn's case wll put Reid in the uncomfortable situation of having to relive the time he was locked up in a prison in Mexico for murder, even though he was innocent.

"It brings up [thoughts of], 'I got out of my prison, literally, and this good man, this agent did not get out of his prison. If I didn't get out when I did, would I have lost my mind? Would you all have not believed in me? Would I have done things that changed me as a human that I regret?' " Messer described of where Reid is mentally.

"He's almost looking in a mirror of this man, who didn't get lucky. Quinn was a good man who thought he was doing the right thing in trying to stop a serial killer, got caught by them and now he is changed forever," she continued. "Reid had an opportunity to be changed by his experience but come out of it stronger, and this man is showing signs that he isn't able to come out of it stronger. There's a bit of 'Why him? Why not me?' Survivor's guilt."

Messer also addressed how the episode will handle Reid's friendship with J.J. (A.J. Cook) and how strong it is. "She pretty much nails [what's going on] in letting him know the differences," Messer says of how J.J. deconstructs Reid's case against Quinn's. "He has a family around who isn't going to let that happen to him."

Finally, the showrunner explained that the close friendship between J.J. and Reid is something that the writers of Criminal Minds thoroughly enjoy exploring.

"We love those two together because they have a bond and a 'Don't keep me out' [understanding]. It's relatable because I would hope that a lot of us have that one friend in our lives who can remind us that we're not alone even if we feel that way or if we feel down and we don't want to open up," Messer concluded. "It's a good reminder to our audience but also to the team that we are always looking out and we always have each other's backs."