CBS' Criminal Minds will be airing its Season 8 finale on Wednesday night, as new still shots for the extended installment, which is titled Brothers Hotchner, have now been posted online.

Actor Mark Hamill, who is best known for playing Luke Skywalker in Star Wars, will make a guest appearance on the highly anticipated episode, and is shown in one of the pictures.

The finale will feature the Behavioral Analysis Unit (BAU) dealing with a peculiar situation, as they'll not only have case to solve, but the Replicator to deal with, who's looking to kill a team member.

TV Guide had previously speculated that Hamill's character, who is quite intelligent, may just be the antagonist.

"Executive producer Eric Messer did share that his character, John Curtis, is 'wicked smart' with a particularly high skill set as it relates to biochemistry, which plays a big part in the episode."

Interesting to note, the CBS network has picked up the popular series for a ninth season.  It will stay in its usual time slot on Wednesday nights.

Criminal Minds is set to air its season finale on Wednesday, May 22 at 9/8 p.m. Central.  Keep checking back for more of the latest details on the crime drama.

Tags: Criminal Minds CBS television