A sharp peal of thunder rumbled, and the pony started to rearand plunge again. . . . Lightening zigzagged across the dark sky,and the frightened pony gave another wild leap that pulled therope through Ken's hand, taking some skin with it. He felt thetears of pain behind his eyelids, but he held even tighter to therope. . . . "It's only thunder, it's only thunder," he repeated softly.When the horse stopped plunging, Ken looked at Bob, who wasbrushing the dirt from his overalls. "Bob, let's name the horse Thunder." Twelve-year-old Ken and his 14-year-old brother, Bob, worked hard on old man Weese's ranch to earn the black mustang. Ken loved the fiery pony with all his heart, but Thunder didn't trust people, and he refused to be tamed.When a forest fire burns the fence posts to the mountain pasture, allowing Thunder and the other wild horses to escape, Ken is heartbroken. Will Ken ever see the black pony again?