'Criminal Minds' Fans Outraged by Matthew Gray Gubler's Absence

One of the members of the Behavioral Analysis Unit was noticeably missing from the first half of [...]

One of the members of the Behavioral Analysis Unit was noticeably missing from the first half of the Criminal Minds two-hour finale.

Matthew Gray Gubler's Dr. Spencer Reid was MIA from the first of two episodes Wednesday while the character is out of town, and fans of the series were demanding an appearance.

Reid was also absent from April 11's episode, which saw an unsub poisoning his victims with rat poison, and Penelope Garcia (Kirsten Vangsness) going back home to deal with a difficult moment from her past.

Fans were not happy about the first hour of the season finale, which saw the team dealing with a man drilling people's heads while trying to stop a phenomenon known as the hole, not featuring their favorite character.

Reid will play a big role on the second hour, the official season finale for the CBS crime procedural, as teased by showrunner Erica Messer.

Messer promised a "surprising" cliffhanger that culminates after Reid 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.

Messer also teased the case will put Reid in an uncomfortable situation, as hell relive the time he was locked up in a Mexican prison 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."

The episode will also deal with Reid's growing friendship with J.J. (A.J. Cook).

"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."

Criminal Minds has not been renewed for a fourteenth season ahead of its finale.