The #1 New York Times bestselling authors return with a scintillating supernatural-themed thriller. Nora Kelly and Corrie Swanson investigate bizarre deaths in the New Mexico desert, but awaken an ancient evil.In the New Mexico desert badlands, a woman''s skeleton is found with two rare artefacts clutched in her hands: lightning stones used by the ancient Chaco people to summon the gods.Was it suicide... or sacrifice?FBI Special Agent Corrie Swanson brings in archaeologist Nora Kelly to investigate. When a second body is found in identical circumstances, they realise the case runs deeper than they imagined.As Corrie and Nora pursue their investigation into remote canyons, haunted ruins, and long-lost rituals, they find themselves confronting a dark power that, disturbed from its long slumber, threatens to exact an unspeakable price.Reviews for Preston and Child''Get ready for the ride of your life'' David Baldacci''Preston and Child know how to craft compelling stories that are both baffling and surprising.'' Associated Press