The New York Times bestselling author brings back the Walker family in a multilayered thriller in which murders past and present connect the lives of three families.Every summer, in an event that is commemorated throughout the Tohono O'odham Nation, the Queen of the Night flower blooms in the Arizona desert. But one couple's intended celebration is shattered by gunfire, the sole witness to the bloodshed a little girl who has lost the only family she's ever known.To her rescue come Dr. Lani Walke...