C.C. MacApp 
All That Earthly Remains [EPUB ebook] 

Dr. Craig was sent by the United States to this remote place in the Andes Mountains to solve a mystery. There had been a nuclear explosion. Who or what was responsible? And what about those five tunnels opening onto the smooth plateau formed by the blast? Dientes told of the Fire Devils — legendary demons who killed with fire balls and lived under the snow. Brulieres, the priest who was the leader of the new totalitarian state was looking for a political answer. Raber and Noriega, a general and lieutenant, bravely entered the tunnels first. No one could have guessed what would happen next.