Teresa, a cabaret star, has to leave her work due to the death of her father. She decides to go to the small village where he lived to meet her brother, Miguel, who is going to marry Marisol soon. Teresa begins to feel attracted to Miguel, and tries to seduce him
Lord Killarney, delegate of the British Museum, acquires in Córdoba, at an auction, an incunabule, a valuable treatise on Arabic botany, but he is killed and the book disappears. The suspicions fall on El Lince, an old-fashioned antiquarian who had bid with the English to get the book. When he is arrested, he asks his nephew to warn Curro Jiménez, who discovers that the famous treaty actually contains the key to accessing a fantastic treasure that a caliph has hidden in the Mosque of Córdoba and that has been, for centuries, cause of deaths and betrayals. But the stolen book is split in half. The other half is, for years, in the power of El Lince, which he bought from the famous bandit Mariano Romero, who has been presumed dead for thirty years.
Angelo Russo, a sixteen year-old girl, is found dead in a river, having been fatally violated with a large blunt instrument. Inspector Di Salvo is assigned to the case and focuses his investigations on St. Theresa's, the exclusive school where Angelo boarded. Three of the murdered girl's classmates, Franca, Paola and Virgina (who call themselves "The Inseparables"), receive threatening poems from an individual using the name "Nemesis". Bizarre "accidents" start to befall the girls: Franca is injured when someone causes her horse to bolt and Virgina nearly breaks her neck on marbles left at the top of a staircase. But Di Salvo is determined to find the killer, even if it means using unorthodox methods. He is aided by Angelo Russo's little sister Emily, whose helpful clues lead to a boutique owned by a dubious character and a vice ring where "rich influential men pay well for teenage favours" ...
