Dr. Angie Rippard is an Arizona wildlife biologist who is drawn into a police investigation when two teenagers are found dead on a golf course that borders protected National Forest Land. Rippard suspects the teens were attacked by a large mountain lion. Rippard believes that the resort was developed too close to wilderness lands, but her plan to relocate cougars in the area provokes the wrath of the resort's owner-Charlie Rutledge-who believes the animals should be exterminated. Deep inside the Tonto National Forest, Rippard and her grad students realize that Charlie Rutledge is hunting them. In a thrilling climax, Rippard must make a choice to kill the cougar that is certain to kill Charlie Rutledge, or kill Rutledge who is certain to kill her. Now we are the endangered species.