The Challenger — Terri Farley

For Phantom, there is only one girl. For Sam, there is only one horse.

Wildcats have been spotted nearby, but they haven't hurt the ranch horses -- yet. So Samantha is outraged when a neighboring rancher vows to kill the cats on sight.

Her family's horses may be safe, but out on the range Sam spots a wild young stallion without a herd. Being alone puts this horse in danger. But can Sam protect the rebellious mustang and still save the wildcats?