In 1956, an airplane crash left the remains of 172 passengers scattered among the majestic cliffs of the Grand Canyon—including an arm attached to a briefcase containing a fortune in gems. Half a century later, one of the missing diamonds has reappeared . . . and the wolves are on the scent.

Former Navajo Tribal Police Lieutenant Joe Leaphorn is coming out of retirement to help exonerate a slow, simple kid accused of robbing a trading post. Billy Tuve claims he received the diamond he tried to pawn from a mysterious old man in the canyon, and his story has attracted the dangerous attention of strangers to the Navajo lands—one more interested in a severed limb than in the fortune it was handcuffed to; another willing to murder to keep lost secrets hidden. But nature herself may prove the deadliest adversary, as Leaphorn and Sergeant Jim Chee follow a puzzle—and a killer—down into the dark realm of Skeleton Man.