For a hundred years the Arizona mountain range known as the Espectros had lured men to its caverns in search of legendary gold and silver lodes. Its shadow loomed ominously over the isolated ranches in the vicinity challenging the adventurous to explore and . To Gary , the lost Mine was more fiction than fact, and the around it too chilling for comfort. Yet with his friend Tucker Browne, Gary decides to explore a new mystery, as each night a flickering light is seen among the rocks. Frightened off by a rifle sho their curiosity is further aroused and the boys are thrown headlong into a mystery in which a variety of suspects vic for their attention. With the all of an Spanish map, the dog and Tucker's cousin Sue, the boys net out once again, this time in search of the Lost Espectro Mine. The elements of good popular mystery are all present in a story that is more proficient and professional than the average.