Kirstie Scott lives at Half-Moon Ranch, where her mother runs a pony trekking centre. She has her own palomino pony and together they love riding the local trails. Storms, floods and earth tremors are all facts of life in this wild terrain, and at times the landscape itself proves the enemy to the horses and riders.

A mystery horse has appeared on Eagle's Peak. He's the perfect Native American mustang - strong, athletic, wilful... And lost! Kirstie names the beautiful Appaloosa Joe. But her attempts to tempt him down to Half-Moon Ranch fail. When two strangers turn up claiming ownership, Kirstie should be relieved; with winter closing in, Joe surely won't survive much longer out on the peak. But somehow she doesn't trust the strangers - and nor, it seems, does Joe...