Marcea is part of a foot patrol in the Mexican desert. She works for the "Fangs" Program, which leased her a semi-automatic rifle following successful completion--at the top of her class--of the program's target-practice skills course. The area she has been assigned to patrol is the rugged, mountainous desert part of the county. She is on the lookout for poachers of ocelots and margays, fanged carnivores that protect riparian zones from overgrazing by vegetarian animals. What she finds instead changes her life forever.