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 trade 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 the fortune it was attached 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.