This intriguing mystery by acclaimed New York Times bestselling mystery writer Nevada Barr is set in Colorado's Mesa Verde National Park where some bizarre deaths take place. It is here that Anna Pigeon finds solace in the cliffs and quiet ruins. Anna is haunted by personal demons and cut off from her friends and family, so she finds some comfort in nature's abandon. But these strange deaths overshadow the calm. People are leaving the park suddenly because they feel ill. Anna searches for answers and the FBI looks for clues and the truth is as menacing as a nightmare.