'Criminal Minds' season 12 spoilers: Spencer's mother returns; 'mayhem within the fandom' teased

"Criminal Minds" season 12 is currently on a hiatus, but the crime drama will finally be back next month with a brand-new episode and a familiar face.

Actress Jane Lynch will reprise her role as Spencer Reid's (Matthew Gray Gubler) mother, Diana, in three episodes of "Criminal Minds" season 12 starting with the upcoming installment, "Surface Tension."

Fans last saw Diana checked into an Alzheimer's treatment study. All this time, she was there, until the program suffered budget cuts. She ended up being dropped from the program altogether.

This is why in "Criminal Minds" season 12, episode 11, Spencer will find his mother Diana roaming around a Vegas casino. This should begin the two relighting their connection.

Executive producer Erica Messer revealed to TVLine that Lynch's return as Diana "kind of resets for us where Reid is with is with his mom and her struggle."

Fans will be treated with a lot more of Reid in "Criminal Minds" season 12. There is an episode entirely centered on him. Messer and cast member Kirsten Vangsness worked together for this installment, which is titled "Spencer."

Fans of the Behavioral Analysis Unit (BAU) agent have reason to worry about Gubler's character in this episode specifically because of the abovementioned collaboration.

The previous times Messer and Vangsness worked together are on episodes that ushered Shemar Moore's exit from the show and led to the death of Jason Gideon's (Mandy Patinkin) death. The Reid-centric "Criminal Minds" season 12 episode won't be any different.

"It is absolutely a change of course [for Reid] — a journey, for him and for the team that I would argue we never even imagined would happen. And yet it happens, and we're along for this ride. And it's an intense one," Messer teased.

It turns out that Reid might not be the only one whose fate will be mapped out in "Criminal Minds" season 12. A.J. Cook, who plays special agent JJ Jareau, teased to TVLine that they will "shock a lot of people."

"We've got some very personal stuff happening to some very loved characters, so there will be mayhem within the fandom. But don't worry, stick with us," she went on to say.

"Criminal Minds" season 12 returns Wednesday, Feb. 1 at 9 p.m. ET on CBS.