Twenty years after his death, the Chilean writer Roberto Bolaño continues to cast a spell, thanks to the wild metaphorical reach of his tumbling sentences, his implausibly encyclopaedic grasp of global affairs and the seductive sense that 20th-century history is a nightmarish riddle to which only literature is the solution. The Savage Detectives and 2666, his best-known books, are at bottom mysteries involving vanished authors – a conceit shared by two new novels conceivably written under his influence. Winner of the Prix Goncourt in 2021, Mohamed Mbougar Sarr’s The Most Secret Memory of Men (translated from French by Lara Vergnaud)...