A Moscow student, after spending the summer with his grandmother in Baku, learns the history of his family. His great-grandfather, a jeweler, a Baku Jew, left for America at the beginning of the First World War, but left a large inheritance... The hero is trying to unravel a family secret, and fantasies-insights lead him to the trail of an ancient diamond, the faults of which are a map of the Caspian oil fields. But this knowledge turns into misfortune...

In the novel by A. Ilichevsky, winner of the RUSSIAN BOOKER prize, solar oil - oil - becomes a philosopher's stone, capable of turning into anything: gold, money, power.