Vampires and vampire bats have one thing in common: they feed exclusively on blood. Hacking through Mexico's jungles, Casey follows caver Scott Davis who discovered a cave he dubbed "the torture chamber." They catch and identify fruit-eating and insectivorous bats, but no vampires. Nearby, a rancher has found signs of an attack: oozing wounds where a bat has made an incision and fed. Casey is vulnerable among the vampires and cattle, but he'll finally be able to untangle truth from tale.