There's a new vigilante in town, and the self-styled crime fighter will have the residents of Oahu fearing for their lives when Hawaii Five-0 returns for season 7.

Five-0 and the Honolulu PD work hard to keep paradise safe for residents and tourists a like, but someone will find their efforts lacking. To pick up the slack, this vigilante serial killer will target his own kind.

"In Hawaii Five-0's season premiere, McGarrett (Alex O'Loughlin) refuses to listen to Danny's (Scott Caan) pleas to take it easy while recovering from surgery after the body of a serial killer is left in the headquarters with an ivory chess piece in his mouth," CBS teased. "When a second serial killer is found dead with another chess piece, Five-0 goes on the hunt for the vigilante as fear grows that it's not safe to travel to Hawaii."

Uh oh. It's always nice to get a few serial killers off the street, but becoming one yourself is not exactly the best way to go about it. The advent of this new menace will cause McGarrett to call in the experts. Cue retired criminal profile Alicia Brown (Claire Forlani).

"Alicia and McGarrett have a profound respect for each other and what they have accomplished professionally," executive producer Peter Lenkov told Entertainment Weekly. "Her insight and expertise as a profiler will be paramount for Five-0 to track down this killer menacing the Island for those who visit and those who call it their home."

See Forlani hanging with our heroes in the photo below: