This letter was written during a séance at the beginning of the Second World War. Czechoslovakia, which boasted over 100,000 active spiritualists and nearly a million sympathizers during the interwar period, was one of the most important bastions of spiritualist creation worldwide. Considered heretical under the Austro-Hungarian Empire, banned by the Nazis, and then outlawed by the Communists, these creations survived in secrecy. It was only in the late 1990s that the public was finally able to discover these works, thanks in particular to the "Czech Art Brut" exhibition at the Halle Saint-Pierre.