The reptilian Gecko brothers, Richard and Seth, are headed south of the border after a gruesome killing spree. Along the way, they kidnap jaded preacher Jacob Fuller and his two teenage kids. When they arrive in Mexico, the quintet pull up to the Titty Twister, the toughest, nastiest, raunchiest biker bar on either side of the border. Unfortunately, the Titty Twister is also home to a nest of violent vampires -- who can transform an hombre into a fellow bloodsucker with just one bite. This sets the stage for the mother of all gore fests, as the Geckos, their hostages, and a few allies use their wits and endless ammo to battle the nocturnal creatures.