MR. SARDONICUS

In 1880, in the fictional central European country of Gorslava, prominent London physician Sir Robert Cargrave visits the mysterious Baron Sardonicus at the urgent request of Robert's former love, Maude, now the baron's wife. Sir Robert becomes apprehensive when his local inquiries about Sardonicus are met with fear. When Sir Robert arrives at Castle Sardonicus, he sees Sardonicus' servant Krull torturing the baron's maid Anna with leeches. Krull mollifies Sir Robert's ire by claiming he was treating Anna with bloodletting.

Maude is afraid of what might happen if Sir Robert refuses Sardonicus's requests. Convinced that Maude despises him, Sardonicus bribes women to his chambers and terrifies the locals with his sadism.

Sardonicus tells his story to Sir Robert. He was born Marek Toleslawski, a farmer like his father Henryk. Marek and his wife Elenka lived a humble life with his father, but Elenka and Henryk wanted more. Henryk bought a ticket for the national lottery but died before the drawing; after his burial, Marek and Elenka discovered that the ticket had won but had been buried with Henryk. Elenka insisted that Marek retrieve the ticket from the grave to prove his love to her. Upon opening the grave, Marek was traumatized by the sight of Henryk's partially rotted, "grinning" face. Marek's face was frozen in a similar horrifying grin, leaving him unable to speak intelligibly or chew food. Elenka, terrified by the transformation, died by suicide. The lottery prize allowed Marek to buy a title and a castle, but he had no one to share them with. Marek renamed himself "Sardonicus" and hired speech experts to retrain him to speak. He conducted experiments on young women to find a cure for his condition, but had no success. He learned from his new wife, Maude, that Sir Robert was a great doctor specializing in paralysis, and hoped Sir Robert could restore his face.

Sir Robert agrees to try, but he is unsuccessful. Sardonicus demands he try more experimental treatments. When Sir Robert refuses on the grounds that they could kill Sardonicus, Sardonicus threatens to mutilate Maude's face to match his own. Sir Robert sends for a deadly South American plant and experiments with diluted extracts on dogs, hoping to develop a variant that will relax Sardonicus's facial muscles without fatally relaxing his heart and lung muscles as well. When Sir Robert balks at using the first variant to have a surviving test subject, Sardonicus coerces him by locking Maude in a room with Henryk's open coffin. This gives Sir Robert an idea: he will inject Sardonicus with plant extract, then recreate the trauma that caused Sardonicus's condition. The operation is a success, and Sardonicus's face is restored. Sir Robert advises him not to speak until his facial muscles have had time to adjust. The baron writes a note annulling his marriage to Maude, and another to Sir Robert asking his fee. Sir Robert refuses any fee, and Sardonicus lets them go.

As they prepare to leave by train, Krull arrives, imploring them to return. Sardonicus has lost the power of speech again, and he cannot open his jaw or lips. Sir Robert tells Krull that the injection was a placebo, and Sardonicus's affliction was only psychosomatic. Once Sardonicus realizes this, he will be completely restored.

Krull returns to the castle. Upon seeing Sardonicus suffering, he puts his hand up to his scarred left eyelid, remembering how Sardonicus plucked that eye out as punishment for disobedience. Rather than relaying Sir Robert's news, he instead tells the baron that he missed Sir Robert's train. Krull sits down to eat his lavish dinner in front of Baron Sardonicus, who continues to suffer, and is doomed to starve.

Sir Robert restores Sardonicus’s face using an experimental treatment and psychological manipulation, and Sardonicus releases Maude and Sir Robert from the castle.

The climax resolves the central horror of Sardonicus’s condition through a combination of medicine and trauma reenactment, leaving the baron outwardly cured but emotionally and morally exposed. William Castle’s meta-ending with the 'Punishment Poll' satirizes the idea of audience agency, but in the film’s narrative, poetic justice is served and the doctor and Maude escape the baron's grasp.