The Sheriff needs help. The baby moose that was the Park City Zoo's favorite is gone! How do you search for a moose in miles of mountains and old mines? With the help of those who hike, bike, and ski all over the Wasatch Mountains - Haley and Nash Barton. A busy football weekend distracts them and evidence points different directions. A trip to the underground museum refreshes their knowledge of the extensive mine tunnels running through the mountains. An underground railway in The Spiro Tunnel once delivered miners two miles into the mountain to the Thaynes Hoistway where they rode to the many mine levels. Skiers rode to the Silver King ski run on the only ski elevator in the world. The tunnel is maintained by Engineer Craig Maceri and his two motorcycle sidekicks, Wayne and Chuck. The Barton's dog, Eiger, applies his acute senses to the moose'strail. Reports in the Salt Lake Chronicle bring the attention of the world. Within the mine, Haley and Nash will face great danger. A rockfall traps them. Invisible carbon dioxide fills the shaft. The hidden secret behind the Missing Moose is untangled in a confidential courtroom showdown only now unsealed and made available to the Public.