Gis le d'Estoc was the pseudonym of a nineteenth-century French woman writer and, it turns out, artist who, among other things, was accused of being a bomb-planting anarchist, the cross-dressing lover of writer Guy de Maupassant, and the fighter of at least one duel with another woman, inspiring Bayard's famous painting on the subject. The true identity of this enigmatic woman remained unknown and was even considered fictional until recently, when...