Lauren Cohan plays a mercenary

The Winchester boys are getting an extra dose of girl power this fall.

Lauren Cohan will join the recently cast Katie Cassidy to help hunt demons on "Supernatural," the CW announced at Friday's (July 20) Television Critics press tour.

On Thursday, Oct. 18, Cohan will jump into the fray as the mercenary Bela, who capitalizes on the money to be had by locking horns with the supernatural world. She joins the fight two weeks after Cassidy has joined up with Dean (Jensen Ackles) and Sam (Jared Padalecki) as a female demon hunter to help wrangle the passel of demons that escaped from hell in the second season finale..

"Ruby and Bela, each in their own unique way, are dangerous, ruthless, more bad than good; and they'll each prove big trouble for Sam and Dean," says series creator and executive producer Eric Kripke. "We were excited to find both Katie and Lauren; they just popped off the screen for us, and they bring charisma and intelligence to their roles."

Cohan's film credits include "Casanova," "Van Wilder 2: The Rise of Taj" and "Young Alexander the Great."