Bibi's summer vacation with her best friend, Tina, got off to an adventurous start. Right from the beginning, the Martin farm was plagued by drought, heavy rain, and severe storms. To make matters worse, the enterprising Kim Win-Win wanted to mine gravel from the ranch. Bibi and Tina had to do something! Would Chico, the mysterious Spanish boy, lend a hand? A tumultuous summer awaited.