Henri Le Clerc was a French Roman Catholic priest and witch hunter. Le Clerc executed 700 witches before publishing Discours du Diable, a book about the practices of the heretics. Only around three of his volumes survived into the 19th century, as most of them were destroyed due to their exploration of dark themes, and his instructions for securing immortality. This involved blood sacrifice, and his great-great-granddaughter Lea Marquis believed that such bloody methods would cure her falling sickness; her father Daniel Marquis sympathized with Le Clerc due to the apparent success of his rituals, calling him a misunderstood man.