Cowboys, western riding and the wide prairie - Bibi and Tina are thrilled when they receive an invitation to Horsehead Ranch in North America. The girls befriend a Native American named Lucy, and her grandfather, who breeds majestic Appaloosa horses. In a struggle to remain on their family's ancestral land, Lucy and her grandfather are faced with a dodgy businessman's plans to take it over. Bibi and Tina decide to help their new friends, unaware of the danger that awaits them...
