Set in the Peruvian Andes, Mario Vargas Llosa's 1996 novel is the second to feature the police officer Corporal Lituma. It begins when he is ordered to investigate the deaths of three members of a road construction crew in the distant mountain village of Naccos. It's a personal matter, since one of the victims was also the mute servant of the corporal's adjutant, Tomas Carreno.

Among the likely suspects are the Maoist guerrillas of the Shining Path (Sendero Luminoso), who are capable of such violence. And indeed, Lituma uncovers a pair of murders committed by the Senderistas, but the victims were French ecologists who they stoned to death. The impoverished, hermetic, and stoic mountain-dwellers (serruchos) he and Carreno question about the fate of the road workers are distrustful of these coastal police, and refuse to reveal anything.

Eventually Lituma begins to realize that he has been misled in his pursuit of the guerrilla group, and senses that the owner of the village cantina, Dionisio and his wife, Doa Adriana, may be responsible for the murders. The corporal and his assistant find that the couple were the leaders of a cult which engaged in drunken bouts of orgiastic sex culminating in a ritual of human sacrifice intended to placate ancient mountain gods. Was it the fate of the three road workers to thus become human offerings to such gods? Despite the absence of physical evidence, Llosa suggests such a conclusion.