Nellie Burns and her Labrador, Moonshine, leap into trouble—this time in Craters of the Moon in southwest Idaho. Sheriff Asteguigoiri recruits Nellie Burns to accompany him to the lava fields as his official photographer. Three people have gone missing in the treacherous landscape, and the miles of lava resist easy navigation as well as Nell's photographic efforts. They enlist a couple of friends to assist in the search. The efforts of Nell and the team yield unusual results—including large sums of money—while the Craters claim more victims. Physical obstacles as well as secrets and lies, cult trappings, and consuming greed endanger the lives and limbs of all, and the members of the search party struggle to overcome the challenges, while Nell faces the most serious attempt yet on her sanity and her life.