In 18th century France, during the last days of the french monarchy in the reign of Louis XVI, the Sanson family, appointed as the royal executioners by the king himself, are struggling with the reluctance of the eldest son, Charles-Henri Sanson, to succeed his father. The story centers around Charles' struggle as a kind, sensitive young man, as he faces his harsh fate as the "Monsieur de Paris", and is changed radically in the process. Over time, the series also begins to focus on his sister, the cold, morbid and rebellious Marie Joseph as she struggles to navigate the patriarchal society of the time to become an executioner herself, and her eventual entanglement with Marie Antoinette.
