Considered by many to be Hammer's finest achievement, though several other of the studio's films rate serious consideration. This one's a solid witchcraft tale written by Richard Matheson. In 1925, the Duc de Richleau (Lee), a "good" warlock, and the evil Mocata battle each other over De Richleau's friend Simon (Mower). Some of the effects are a little dated now, but director Terence Fisher builds suspense through a stately pace. Production values are highlighted by the usual excellent sets and a fleet of vintage cars. Lee's performance is one of his strongest in a conventionally heroic role.