A stormy night shakes up Martins Farm... The paddock fence is damaged and the mill farmer is angry, claiming one of Mrs. Martin's horses trampled his vegetable garden. Or was it the mysterious black horse that Bibi thought she saw in the moonlight? The friends set off in search of the horse - only to discover a beautiful, wild stallion in the quarry. Bibi can only calm him with a spell, but where does he come from? Who does he belong to? And will Bibi and Tina succeed in taming him?