A trunk in a seaside villa contains old papers: press clippings, notebooks, packets of love letters, a receipt for a deposit in Berlin, theatre programmes. It all comes from Uncle Louis. A discreet, unassuming figure, Louis is like a character in a novel. This is how the newspapers portrayed him when he was arrested for Soviet espionage in December 1933. He was head of the cipher department at the Ministry of the Navy. He was allegedly the lover of a Russian exile, Lydia, who worked for the film industry and sold counterfeit dollars made in Moscow.

Step by step, Pierre Cassou-Noguès retraces Louis' life, his travels, wars, Bolshevism, prison, love affairs, in order to understand who this uncle was and what is the identity of a character,  when this character belongs to life, rather than a novel. Louis and Lydia are elusive, as if they had escaped the words they use in their letters, as well as the detectives of the Sûreté Générale. The investigation, which takes us from Arcachon to Berlin, from Paris to New York and into the archives of the FBI, comes to nothing. We don't find out if Louis was a Soviet spy or a naive fool, if he was Lydia's lover or if their affair was just a cover for other loves. In the end, none of this matters very much.