A new attractive and unexpected killer will shake things up in Season 10 of "Criminal Minds."

Unlike most of the killers featured on the long-running CBS procedural who happen to be men, the BAU will be tasked with hunting down a female villain. According to TVLine, the killer will be an "extremely attractive" and "successful" career-oriented woman in her thirties, who has a bit of a temper. Her character is described impulsive, emotional and "prone to sudden rages." She will make her debut in the ninth episode of the new season.

In addition, TV viewers will also be introduced to Rossi's second wife in a 90's flashback scene in the same episode.

TVLine also revealed that Teen Wolf star Ian Nelson will make an appearance in Season 10 as an emotionally complex teenage who experiences harassment in the form of morbid selfies posted on the Internet.

Fans can also look forward to seeing actress Jennifer Love Hewitt playing as FBI agent Kate Callahan on the show, reports Entertainment Weekly.

Hewitt was cast in a reoccurring role on the show in lieu of actress Jeanne Tripplehorn who left the show in last season's shocking finale.

Tripplehorn's character Alex Blake was one of the main characters on the show. However, Blake made a sudden exit after she was traumatized over Spencer Reid's gunshot injuries. As a result, she decided to quit her job on the FBI's elite Behavioral Analysis Unit (BAU).

Although Kate Callahan will be introduced in the debut of the new season, viewers won't learn much about her. According to TV Guide, Hewitt's character will come full circle after she becomes involved in a case with a plane crash that hits close to home.

"Although she'll fill in the blanks to at least one member of the BAU, he or she may not be the first person to find out," TV Guide reported.

The season premiere of "Criminal Minds" airs on Wednesday, Oct. 1, on CBS.