CBS’ favorite crime series, “Criminal Minds,” will finally return today after two weeks. Last time we saw the procedural, Interpol Agent Emily Prentiss (Paget Brewster) returned to the BAU (Behavioral Analysis Unit) in order to help with their mounting caseload. This week, the Halloween-themed episode promises thrills, chills and a surprising news for Dr. Spencer Reid (Matthew Gray Gubler).

In a sneak peek video released by CBS, Reid, David Rossi (Joe Mantegna) and Jennifer “J.J.” Jareau (A.J. Cook) discuss a case when the Ph.D. holder’s cell phone rings. While J.J. and Rossi are brainstorming on how the Unsub killed its victim, Reid attends the call.

Once he’s done with the call, Rossi and J.J. ask him if everything is O.K. Reid then reveals that the call was from the Los Angeles Police Department. They informed him that his schizophrenic mother Diana (Jane Lynch), who is now also suffering from dementia, was found wandering around a casino.

Rossi then insists that Reid take a day off and spend it with his mother even though they are in the middle of a case. This little call no doubt sets up a huge storyline for Reid in the upcoming episodes on “Criminal Minds” and paves the way for Diana’s appearance in Season 12, episode 11.

“[Her return] will be good,” the show’s executive producer, Erica Messer, told TVGuide about Diana’s return, “That’s why everybody’s excited. It was more important than ever to have Jane come guest-star because it will be a big story.”

The “Glee” star will reprise her role as the profiler’s mother after eight long years. She will be a part of a huge storyline for the doctor.

Meanwhile, today’s episode will see the BAU hunt a serial killer who has killed seven people. Their investigation will lead them into the woods in rural Virginia.

“Criminal Minds” Season 12 airs Wednesdays at 9 p.m. EDT on CBS.

Criminal Minds “Criminal Minds” Season 12 returns today, Oct. 26 with an episode that shows the BAU hunting an Unsub in rural Virginia. Catch “Keeper” at 9 p.m. EDT on CBS. Photo: CBS