The correspondence opens in 1936, the year Canavaggia became Céline's literary secretary. She was thirty-nine, from a Corsican intellectual family in Paris, and worked from her apartment.
The early letters cover the preparation of Bagatelles pour un massacre (1937), L'École des cadavres (1938) and Les Beaux draps (1941) — instructions on typing, corrections to send to publishers, disputes over paragraphs and cover copy.
The wartime letters thin. Céline is in Paris under the Occupation and then, from 1944, in flight. Canavaggia keeps working from Paris; the material she was custodian of survives, and later feeds into the manuscripts that were only rediscovered in 2021.
The Danish exile letters (1945–1951) are practical and urgent. Céline is in Copenhagen — first at Vestre Fængsel, then living under surveillance in the country — and Canavaggia is his channel to French publishing, editors, lawyers and money.
After 1951 the correspondence covers the return to Meudon and the composition of the German trilogy: D'un château l'autre, Nord and the still-unfinished Rigodon. Canavaggia types, reads, corrects and forwards proofs.
The final letters are dated 1960. Céline dies in July 1961. Canavaggia continues as a custodian of the papers into the following decades.