London’s society reacts indignantly to the news that Lord Montbarry has broken off engagement with Agnes Lockwood, and is going to marry Countess Narona. Countess Narona is known as a swindler and adventuress in Europe and England. She is said to be greedy for money, and everyone sees a trick in the fact that Lord has insured his life for the sum of ten thousand pound, and in the case of his death the money would be passed to his widow. But nobody sympathizes with him, because all the pity feelings are given to poor Agnes Lockwood, the woman he has left. Nevertheless, Lord and Countess get married and leave for Venice. There they rent a palazzo and lead there a rather reclusive life. They are accompanied by the Countess’s brother Baron Rivar, and by their courier, Mr. Ferrari, who, by the way, is recommended to this position by Miss Lockwood, as Ferrari’s wife was Agnes’s maid, and asks her to help to get this position for her husband.
Soon the news comes to London that Montbarry has died of bronchitis. Mr. Ferrari has disappeared, and nobody knows where he had gone. His wife receives an anonymous letter with a banknote of one thousand pound. The insurance companies hold a careful investigation of the Lord’s death, but find no evidence that would claim that Montbarry died in an unnatural way. So, the companies have nothing to do, but pay the widow the money. Soon Countess and her brother leave for America.
Meanwhile, the palazzo where Lord had died, is remade into a fashionable hotel, and the Westwicks arrange to meet there in few months, when everything will be done, and the hotel will open. The room in which Lord Montbarry died had been arranged into one of the most fashionable rooms in the hotel, and without realizing it, three of his close relatives had spent night in it. Each of them experiences sleeplessness, nightmares or nauseous smells. When Agnes happens to sleep in it she observes a disembodied head descending from the ceiling in the night. In the morning Agnes is found unconscious in the room. Henry Westwick, who cares about Agnes very heartily, tries to find out the matter.
In few months countess Narona happens to be in Venice, compelled there, as she says, by destiny. Henry has a conversation with her, but only becomes convinced that she is going insane. Pangs of conscience continue torturing her, but the reason is still unclear. Next day Countess brings Henry a ghost play written by her, and asks to read it. She says that it is fiction, but the events put in the play make Henry shiver with fear.
The story is a confession of Montbarry's murder by her and her brother. Soon after the wedding Lord understood that she and her brother needed money, and did not give them any. At that time Lord suffered a light fever, and their courier Ferrari was dying of bronchitis. At that moment Countess came up with an awful plan. She and her brother convinced Mr. Ferrari to take Lord Montbarry’s place, and die instead of him, while they would take care of the true Montbarry. Ferrari asked one thousand pound, and they agreed. Mr. Ferrari died being Lord Montbarry, true Montbarry was poisoned, and his body was disposed by acid. Only his head was hidden in a secret compartment in the fireplace.
Having read this Henry hurries to Countess for more explanations, but she is already dead when he comes. The next day the head is found in the fireplace’s secret cabin, but nobody believes that it is Montbarry, as it is absurd to trust the madwoman’s words.
Only Henry knows the truth, as he has taken a set of gold false teeth, which later are confirmed as Montbarry's. But Henry never told anybody about this.
Soon after the sad events Agnes and Henry return to England and get married. Never ever they returns to the conversations about Countess and lord Montbarry.
