In the next episode, an unsub creates a giant sundial out of his victims. Meanwhile, Shemar Moore shares how he feels about returning to the show for the finale.

On the next episode of "Criminal Minds" season 12, titled "True North," the BAU encounters an unsub that creates a giant sundial from its victims by tieing them up in the desert.

"The BAU is called after three victims are found tied to stakes in the Arizona desert," the episode listing reads from The Futon Critic.

As seen from the episode 19 promo, JJ (A.J. Cook) figures out that their unsub created a sundial using his victims based on the evidence that they have gathered. This episode was directed by Joe Mantegna who plays David Rossi on the show, just like episode 7, titled "Mirror Image."

Meanwhile, Moore has been confirmed to return in the season 12 finale of "Criminal Minds" to reprise his role of Morgan. Morgan will be bringing new evidence to the BAU that will help them catch Mr. Scratch and get Reid (Matthew Gray Gubler) out of prison once and for all.

In a Facebook Live interview with Entertainment Tonight, Moore revealed that he's missed playing Morgan on the show and that he's very much excited to return to the series.

"I was so blessed to do 11 years on Criminal Minds and bring Derek Morgan to life. Flirt with my original 'baby girl' Penelope Garcia (Kirsten Vangsness), chase all the UnSubs and bad guys and kick down doors. I miss it, but one door closes and another one opens," Moore explained.

Moore added that the reason he left the show was "nothing negative or unhappiness." It was hard for the actor to leave, but he also explained that he's a dreamer and that he doesn't regret any of his decisions.

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