Cinematical has just received the dark new poster for Cirque Du Freak: The Vampire's Assistant, an adaptation of a young adult book series by Darren Shan. The film version stars John C. Reilly as a vampire -- which is enough to sell me on the movie right there!

But, for those who must know more, the official synopsis says in part that the movie is "a fantasy-adventure about a teenager who unknowingly breaks a 200-year-old truce between two warring factions of vampires. Pulled into a fantastic life of misunderstood sideshow freaks and grotesque creatures of the night, one teen will vanish from the safety of a boring existence and fulfill his destiny in a place drawn from nightmares." Chris Massoglia plays a 16-year-old boy who becomes the assistant of a vampire named Larten Crepsley (Reilly). Among the assistant's new friends are Salma Hayek as a bearded lady (?!) and Ken Watanabe as a "gigantic barker." Josh Hutcherson also stars.

The film takes its title from the second installment in the 12-book series, The Saga of Darren Shan, but the script combines elements from the first three books. Directed by Paul Weitz (In Good Company, American Dreamz), look for Cirque Du Freak: The Vampire's Assistant in theaters on October 23, just in time for Halloween.

Have a look at the full-sized poster in the gallery below. The complete synopsis is available after the jump. And keep an eye out for the trailer, which will debut on Moviefone tomorrow.