Since 1955, Jean Mermoz's letters have rested in his mother's vault at Mainbressy, in the Aisne. However, Christian Melchior-Bonnet, her literary executor, had the wisdom to have these letters photographed or copied: a precious first-hand testimony — moving and plain, amusing or tragic — which he preserved for more than thirty years. This correspondence restores in its own way the uncompromising character of Mermoz: his touching naivety, his formidable determination, his courage that even seasoned wartime pilots found remarkable, his filial love, his impulses, his hopes, but also his anger and his disillusions. These letters (to his mother, his grandparents, Guillaumet, his friends) reveal the evolution and maturation of a man who loved his profession, accepted its risks, and sacrificed his life to it. The book includes 5 chapters, each representing a distinct period in Mermoz's life, preceded by a biographical text placing the letters in their context.