"You'll never catch the Phantom," says Grandpa. "That horse is fast as the wind. She's escaped from every roundup on the island!"

But Paul and Maureen want the beautiful wild mare for their very own. "I'm going to capture her myself," says Paul.

When Paul finally overtakes the Phantom, he makes a surprising discovery. Running at her side is a brand-new, silvery-gray colt - Misty!