CBS’ “Criminal Minds” finally progressed Dr. Spencer Reid’s (Matthew Gray Gubler) storyline in Season 12, episode 20. Last week, his lawyer, Fiona Duncan (Jeananne Goossen), informed him that his trial has been pushed back by six weeks. The poor profiler will stay in prison for a while longer. Meanwhile, the FBI’s Behavioral Analysis Unit (BAU) worked on a case that involved victims experiencing symptoms of a heart attack.

However, the real plot twist in the episode came towards the end when Reid’s mother Diana (Jane Lynch) visited her son in prison. She had fired the competent nurse that he had hired to take care of her. Then, he met her new nurse. And guess who it was? Lindsey Vaughn (played by series regular Joe Mantegna’s daughter Gia).

READ: Reid’s mother provides a huge break in her son’s case.

In fact, Lindsey is the woman Reid remembers being with when the doctor was killed in Mexico. That’s right: Lindsey is behind the profiler’s prison storyline.

The shocking fact comes as “Criminal Minds” is beginning to wrap up Season 12. What will happen on Wednesday’s episode of the CBS series?

Unfortunately, things are going to get worse for Reid. The synopsis of Season 12, episode 21 on TVGuide reads, “When Reid fears his mother has been abducted, he asks the BAU to investigate while he’s stuck in prison.”

If Reid loses Diana, he could completely break down. In the promo of this episode, which is titled “Green Light,” BAU Chief Emily Prentiss (Paget Brewster) informs her team that she has been abduction. Of course, news of his mother’s kidnapping sends Reid over the edge. A prison guard is seen holding the triple Ph.D. holder down after he hears the news. Poor Reid.

Prentiss rightly tells her team members in the video, “If we lose Diana, we lose Reid forever.”

The BAU works extremely hard to find Diana and comfort Reid. Towards the end of the clip, we see Reid dressed in a tuxedo and meeting someone. Is it Lindsey? Cat Adams (Aubrey Plaza)? Mr. Scratch (Bodi Elfman)? It’s hard to tell since their voice is distorted. Whoever it is, “Criminal Minds” promises a big reveal at the end of the episode.

Episode 21 is the penultimate episode of Season 12. The season finale airs next Wednesday, May 10 at 9 p.m. EDT on CBS.

“Criminal Minds” showrunner Erica Messer told TVLine that Reid’s journey would come to satisfying end in the Season 12 finale. There will be some surprises in store for long-time fans of the procedural. One such surprise will be dropped by Derek Morgan (Shemar Moore) and Mr. Scratch certainly plays a role in the final moments of the season.

Unfortunately, Season 12 will end on a cliff-hanger and will set the stage for Season 13. “Criminal Minds” has already been renewed for another season.

“Criminal Minds” Season 12, episode 21 airs Wednesday, May 3 at 9 p.m. EDT on CBS. The finale airs next Wednesday, May 10 at 9 p.m. EDT.