In this emotion-packed addition to the bestselling Leaphorn, Chee, Manuelito series, Officer Bernadette Manuelito puts her life at risk as she works with Leaphorn to uncover a plot that involves money, mustangs, fractured family ties, clever lies and long-held grudges—a potentially deadly assignment that challenges her beliefs about good and evil.

When Bernie and her sister Darleen planned their trip to the sacred Canyon de Chelly, they expect a quiet, thoughtful, healing journey. But instead of tranquility, they encounter murder and mystery between the canyon's towering walls. The trouble begins when Bernie spots an anxious woman at one of the canyon’s overlooks and offers to help. Later, a security guard discovers the woman’s body in a stolen tent, and Bernie and Darleen soon find themselves sucked into a vortex of dark deceit.

While the FBI questions Bernie, Darleen joins a group of children and their teacher on a guided tour of the Canyon, a sacred place to the Navajo. Darleen hopes to photograph mustangs and unique rock art created by the area’s earliest inhabitants. But the scenic trip takes an ugly turn when the group is stranded deep within the canyon and Darleen learns that their driver shared a close connection with the mysterious dead woman.

Back in Shiprock, Jim Chee investigates the theft of Navajo horses connected to illegal mustang roundups. Digging deep into the case distracts him from another issue: a possible promotion that could compound the stress on his marriage to Bernie.

Meanwhile, Joe Leaphorn’s latest private investigation—the search for a missing scientist—leads him to contact Bernie and Chee. Working together, the trio face complex issues involving human and equine genetics—questions which draw them into to a life-threatening situation and tie the mustang and human bloodlines together.