"Criminal Minds" season 11 is set to air another gripping episode as the BAU seeks to track down an unknown criminal who captures and disfigures his victims.

Titled "Inner Beauty," the team at the Behavioral Analysis Unit (BAU) of FBI is set to go after a scary crook who is in the practice of defacing his victims after catching them. Based on their investigation, the criminal they are going after has an obsession with transforming beautiful faces to make them look ugly.

Promo trailer for "Criminal Minds" season 11 episode 20 shows Dr. Spencer Reid explaining to the team that the unknown criminal conducts some odd rituals to his victims before transforming their pretty faces into ugly ones.

 The promo clip also suggests that the criminal may have some unstable mental state, as there is a scene in the trailer showing blond-haired dolls lined up, all with open cracks on the right side of their faces. The facial disfigurement is also hinted at in the clip, as agent Jennifer Jareau says: "He remakes them so he could destroy them."

According to Dr. Reid, the criminal wants his victims to reach a certain level of ugliness because that is when he finds them beautiful.

"To him they're more beautiful," says Dr. Reid to the team.

His assessment seems to be right. In the trailer, the mysterious criminal is shown talking with a weeping victim, saying, "Who else is going to love you the way I do?"

The episode will also feature an awkward encounter between agent David Rossi and his ex-wife Hayden Montgomery.

"Criminal Minds" season 11, episode 20 airs on CBS on April 13.