Reid (Matthew Gray Gubler) learns that his mother has been abducted and that Lindsey (Gia Mantegna) might be behind it. Meanwhile, Reid might finally face Mr. Scratch, and he might be surprised of his identity.

On the next episode of "Criminal Minds" season 12, titled "Green Light," Reid will learn that his mother has been taken.

"When Reid fears his mother has been abducted, he asks the BAU to investigate while he's stuck in prison," the episode listing on The Futon Critic reads.

As seen from the episode 21 promo, Prentiss (Paget Brewster) will be the one to confirm to Reid that his mother has been taken. She tells the BAU, "If we lose Diana (Jane Lynch), we lose Reid forever."

The person who might be responsible for Diana's abduction is Lindsey. In the previous episode of "Criminal Minds" season 12, titled "Unforgettable," it was revealed that Lindsey is pretending to be a woman named Carol Atkinson, who happens to be Diana's new nurse.

With the season ending with its two-part finale, the show will finally reveal how Lindsey is connected to Mr. Scratch, who is presumed to be responsible for Reid's frame up.

Meanwhile, it appears that Reid will finally come face to face with Mr. Scratch. On the latter part of the episode 21 promo, Reid enters a room where a woman is sitting and says to him, "You didn't expect me, did you?"

If the woman inside the room is Mr. Scratch, then it would completely have kept the whole BAU blindsided.

However, Shemar Moore will return in the finale episode as Derek Morgan to bring a lead that will help them catch Mr. Scratch. This implies that the woman that Reid will be seeing might only be an accomplice of Mr. Scratch.

"Criminal Minds" season 12 airs every Wednesday night at 9 p.m. EDT on CBS.