内容简介：
The treacherous mountains surrounding the Canyon of Death loomed over them. High up near the peaks was the cave where giant flying raptors had carried Captain Luke and Gridley. Arnold and Pudge trudged up the narrow, icy, mountain path. One false step meant plunging to their deaths. Mysteriously endowed with incredible strength and courage, Arnold faces one crisis after another on the spaceflight to a newly- discovered Martian moon. Would they survive? Would they get back to Earth? Only Mr. Sprock, the peculiar copilot, has the answers. Now, all the boys have to do is find him.