"The Caliph Harun-al-Rashid...one night, in the grip of insomnia, disguises himself as a merchant and goes out into the streets of Baghdad. A boat carries him along the waters of the Tigris to the gate of a garden. At the edge of a pool a maiden beautiful as the moon is singing, accompanying herself on the lute. A slave girl admits Harun to the palace and makes him put on a saffron-colored cloak. The maiden who was singing in the garden is seated on a silver chair. On cushions around her are seated seven men wrapped in saffron-colored cloaks. 'Only you were missing,' the maiden says, 'you are late'; and she invites him to sit on a cushion at her side. 'Noble sirs, you have sworn to obey me blindly, and now the moment has come to put you to the test.' And from around her throat the maiden takes a pearl necklace. 'This necklace has seven white pearls and one black pearl. Now I will break its string and drop the pearls into an onyx cup. He who draws, by lot, the black pearl must kill the Caliph Harun-al-Rashid and bring me his head. As a reward I will give myself to him. But if he should refuse to kill the Caliph, he will be killed by the other seven, who will repeat the drawing of lots for the black pearl.' With a shudder Harun-al-Rashid opens his hand, sees the black pearl, and speaks to the maiden. 'I will obey the command of fate and yours, on condition that you will tell me what offense of the Caliph has provoked your hatred,' he asks, anxious to hear the story."

This relic of some childish reading should also be included in your list of interrupted books. But what title does it have?
"If it had a title I have forgotten that, too. Give it one yourself."
The words with which the story breaks off seem to you to express well the spirit of the Arabian Nights. You write, then, He asks, anxious to hear the story in the list of titles you have asked for in vain at the library.

If on a winter's night a traveler, Italo Calvino (1979)