Volpi’s most famous book, 'En busca de Klingsor' ("In Search of Klingsor", 1999) is a novel that fuses a story of Nazi generals in World War II and the history of physics. In this novel an American physicist and a German mathematician are on a mission to discover information about Klingsor, the codename for the person in charge of the Nazi party's scientific research. On their odyssey the two are lead to some of the greatest scientists of all time. For his work on this novel, Volpi won the Spanish literary prize, Premio Biblioteca Breve, in addition to the French Deux-Océans-Grinzane-Cavour-Prize.