Jim watches over a zoo, ensuring animals don't escape and humans don't hurt the animals. When he sees a boy standing in front of the lion's den for over an hour, he gets the feeling something's wrong and goes to investigate. Just as he arrives, the boy climbs over the enclosure and joins the lions. Jim and his coworkers watch helplessly as these predators circle the boy, unable to tranquilize the animals without provoking violence. Suddenly, the lights in the zoo short-circuit. By the time they can see again, the boy is gone - as is every trace of him, even the blood that should be left behind by a mauling. After his disappearance, animals behave strangely, running from zookeepers and defying pack instincts. A ghostly lion gets spotted prowling the zoo, only to disappear upon investigation. Concerned, the managers hire more security. The new guards antagonize the animals, until an incident occurs. Obscured on camera by a tree branch, something attacks the guards while they humiliate orangutans, killing one and tearing the face off of the other. After these horrors, the zoo announces it'll be closing. The animals often run free from their pens, flocking together in ways they shouldn't, exhibiting unnatural behaviors. Jim's coworker decides to return to grad school and study their new behavior patterns. Jim is left wondering if these animals will recreate the same behaviors when they're shipped off to zoos across Europe.