Les-Eyzies-de-Tayac is known for three things: pâté de fois gras, truffles, and prehistoric remains. The little village, in fact, is the headquarters of the prestigious Institute de Préhistoire, which studies the abundant local fossils. But when a pet dog emerges from a nearby cave carrying parts of a human skeleton—by no means a fossilized one—Chief Inspector Lucien Anatole Joly puts in a call to his old friend, Gideon Oliver, the famed "Skeleton Detective."
Once Gideon arrives, murder piles on murder, puzzle on puzzle, and twist follows twist in a series of unexpected events that threaten to tear the once sober, dignified Institut apart. It takes a bizarre and startling forensic breakthrough by Gideon to bring to an end a trail of deception thirty-five thousand years in the making.