Earl Hammond, the wealthy patriarch of a family of ranchers, lies dead, shot just as he was to donate his Coquina Ranch to the state to preserve it from developers. Spearheading the plan to save this environmental treasure was Thorn, a reluctant heir to a secret family fortune, who now finds himself in terrible danger as well. A pair of deviant brothers, both contract killers, kidnaps him and drags him to a game preserve, surrounded by herds of exotic and very dangerous animals. He is entrapped in a sinkhole—a geological dungeon from which there is no escape.