Böll tells of Dostoevsky's grandson, a Leningrad engineer

Böll tells of Dostoevsky's grandson, a Leningrad engineer. Having retired, he became a tireless, meticulous researcher and biographer of his grandfather. He made us count the steps from "Raskolnikov's house" to "the pawnbroker's house", and showed us the door behind which the axe had been hidden. He lamented that the several Marmeladov apartments he had discovered did not match the descriptions, and said confidentially: "Probably, in the novel, the apartment is, so to speak, synthetic..."
Böll answered him quite seriously:
"You are, of course, right. Writers sometimes make such syntheses."

From the memoirs of the literary scholar Lev Kopelev.