'Criminal Minds' season 12 episode 13 spoilers: Spencer-centric arc kicks off in Mexico; Harold Perinneau to star in recurring role

A game-changing episode is coming to "Criminal Minds" this week, and Dr. Spencer Reid (Matthew Gray Gubler) may be at the core of a not-so-favorable plot shift.

Simply titled "Spencer," the episode finds a member of the Behavioral Analysis Unit (BAU) in a tight pinch in Mexico. This member is undoubtedly the episode's titular character himself, and if the rest of the team will have to enlist the services of the International Response Team (IRT) in order to help him, then he must be in seriously deep trouble.

The IRT is an elite team of agents from the Federal Bureau of Investigation (FBI) who are relied on to take care of cases involving American citizens on international soil. Their exploits are chronicled in the spin-off series "Criminal Minds: Beyond Borders." Two of the characters from the said show, Clara Seger (Alana de la Garza) and Matthew Simmons (Daniel Henney), will be crossing over to the main series to lend a hand in Spencer's case.

The trailer for the next episode reveals more details about Spencer's predicament. He will apparently be imprisoned in Mexico and charged with a murder he does not remember committing. Has his stressful life finally caught up to him and pushed him to the dark side, or is he simply being framed for something he does not even seem capable of doing? Will the combined forces of the BAU and the IRT be enough to uncover the truth that gets Spencer out of prison, or will a shocking discovery about the man they think they know lead to an unforeseen outcome?

In a recent interview with TV Line, executive producer Erica Messer teased that this particular episode will be launching "a journey for [Reid] and for the team that I would argue we never even imagined would happen."

This arc also ushers in a recurring character named Calvin Shaw, a former FBI agent imprisoned for killing one of his informants, who will first appear in episode 15 and will be played by "Lost" alum Harold Perinneau.

"Harold is awesome, as a person and as an actor, and what he brings to this world and this back 9 is such an interesting perspective and a depth, for not only him but for Reid," Messer said.

"Criminal Minds" season 12 episode 13 airs on Wednesday, Feb. 15, at 9 p.m. EST on CBS.