'Criminal Minds' Finale Leaves [Spoiler] in Grave Danger

Criminal Minds teased a shocking season finale cliffhanger, and they delivered for sure.

By the end of the two-hour finale, viewers were shocked to find two fan-favorite characters in grave danger, Penelope Garcia (Kirsten Vangsness) and Spencer Reid (Matthew Gray Gubler).

During the finale's second hour, Reid returned from a two-episode absence, discovering FBI Special Agent Owen Quinn (James Urbaniak) locked inside a storage unit after being missing for a year.

While severely traumatized by being imprisoned for so long, the members of the Behavioral Analysis Unit question the story behind finding Quinn, who quit the FBI after the agency wouldn't categorize an UnSub he named "The Strangler" as a risk. Reid reveals he was led to the storage unit by an anonymous email telling him where he could find Quinn.

#CriminalMinds pic.twitter.com/ayBGfo2PQE

— Criminal Minds (@CrimMinds_CBS) April 19, 2018

J.J. (A.J. Cook) reaches out to Reid, concerned by him keeping secrets and going to search for Quinn without anyone else from the team, which she claims is related to the time when Reid was imprisoned in Mexico for a crime he didn't commit.

Reid interviews Quinn, who claims he will not be safe until The Strangler is arrested. He claims the case involves a family of UnSubs, who kidnapped and tortured him for a year.

Later, J.J. and Matt (David Henney) interview Quinn's family. His son claims his father was a good man before he mysteriously disappeared, but his wife says he became so obsessed with capturing the UnSub that he started threatening her, which is when she kicked him out of the house and filed for divorce.

As Reid became frustrated with Quinn's bizarre story, he finds out the UnSub family's son, who Quinn named Theo, took the class he taught, which explains how the anonymous tip ended up in Reid's hands. The team finds the family's home but encounters the parents shot to death with Quinn's gun, and Theo nowhere to be found.

The BAU uncovers that Theo's girlfriend April is missing as well and when Reid questions Quinn about her whereabouts, he reveals she was also kidnapped by Theo's parents and they almost forced him to kill her, but Theo knocked him unconscious and killed his parents before stuffing Quinn in the storage unit.

After killing his parents, viewers see Theo lose control and kill two people at an empty subway station, but there's a twist.

Reid and Quinn find Theo and April at her family's second home, and they reveal they are hiding from a cult of murderers known as the Believers, who will stop at nothing until they are dead.

The team finds the cult leader's — who calls himself the Messiah — hiding spot and arrest him.

As The BAU celebrates capturing the dangerous man, Prentiss realizes Quinn might be a member and could try to free the Messiah. Then things take a turn for the tragic as Garcia (Kristen Vangness), who is on her way to join the rest of the team, finds herself on an elevator with Quinn and another FBI agent.

Reid, who also stayed behind, is startled by a gunshot and rushes toward the elevator where he finds Quinn injured. Turns out, the other agent is a servant of the Messiah and has captured Garcia.

The season ends with the agent threatening to kill Garcia if Reid doesn't help her free the Messiah, as Garcia screams telling Reid to not compromise himself for her.

Criminal Minds has not been renewed for a fourteenth season by CBS yet.