Book 13) Jack has become the most decorated secret agent for the Global Protection Force, but during the day he's still just an ordinary kid who has to put up with annoying people -- like Marko Mayer, a new student in Jack's rock-climbing class. When Jack and Marko race to the top of the wall, Marko stomps on Jack's hand and wins -- then has the nerve to gloat! But Jack has no time to sulk -- the GPF needs him in Nepal. A plane carrying a team of scientists has gone missing over Mount Everest. They were thought to be carrying the first true Yeti skull ever recovered -- proof that the legendary Abominable Snowman really existed. Jack quickly discovers that a greedy collector is behind the theft -- and he may have hired Jack's archnemesis for the job. Can Jack and his fellow agents use their climbing skills to brave the highest mountain on earth and recover the priceless skull?