The Mystery of Joan of Arc is an essay (or short book) on the legendary French saint, which Arthur Conan Doyle translated and augmented from the French original by Léon Denis. In this spiritualist-flavored biography, Doyle (and Denis) re-examine Joan of Arc's life – her voices, visions, and miraculous feats – through a paranormal lens. They posit that Joan's guiding "voices" (St. Michael, St. Catherine, etc.) might be understood as spirit guides or psychic intuitions in modern terms. The work combines historical narrative with spiritualist interpretation: recounting Joan's humble origins, her divine mission to drive out the English, her battlefield successes, and her trial and martyrdom. Doyle dwells on the mystery of how an illiterate peasant girl could so profoundly alter history, suggesting the answer lies in the unseen influences guiding her. He uses Joan as a example of mediumship or divine intervention that even skeptics must respect. Additionally, the text champions Joan's character and legacy – painting her as a pure vessel for higher power. The Mystery of Joan of Arc is thus part history, part spiritual inquiry, delivered in an admiring tone. For Doyle, a devout spiritualist and chivalry enthusiast, Joan's story validated the idea of "voices from beyond" leading mortals to righteous action, and he conveys that with reverence.

Sir Arthur Conan Doyle (1859–1930) was a Scottish author, physician, and spiritualist best known for creating the legendary detective Sherlock Holmes. Born in Edinburgh, he studied medicine at the University of Edinburgh, where his storytelling talent began to emerge alongside his scientific education. Though initially practicing as a doctor, Doyle turned to writing to support himself, eventually achieving worldwide fame with the publication of A Study in Scarlet in 1887. Beyond detective fiction, he explored historical novels, science fiction, and supernatural themes, notably in the Professor Challenger series. A passionate advocate for justice, he was involved in several real-life legal investigations. In his later years, Doyle became deeply involved in spiritualism, dedicating much of his time and writings to life after death. His legacy endures as one of the most influential figures in literary history.