During the reign of France's King Louis XIV, Danielle Darrieux stars as Mme de Montespan, who is, to use the common 17th century euphemism, a "favorite" of the French monarch. When she is cast aside by His Majesty, Mme. De Montespan schemes to discredit her rival for Louis' affections. Conspiring with defrocked priest Guibourg (Paul Meurisse) and fortune teller La Voisin (Vivienne Romance), the "heroine" begins to poison a number of aristocrats close to the king, then plants evidence suggesting that her rival is responsible. The film accommodates any number of lurid (but historically accurate) sequences, including a harrowing torture-chamber episode.
Source : allmovie.com