The General says that Bertha grew more ill, and the doctor was unable to figure out what was wrong with her. He suggested the General send for a physician from Gratz, who arrived and examined Bertha. However, the other doctor, upon hearing the physician's diagnosis, scorned his ideas. The General is disappointed, but the physician insisted that there was no natural explanation for Bertha’s illness, and that she was very near death. However, he suggested that there may be hope if another attack were avoided. The General inquired what he believed the nature of the illness was, and the physician handed him a letter and told him not to open it until he was in the presence of a clergyman.
The two doctors disagree over the validity of a non-natural explanation for Bertha’s illness. When the first doctor hears the diagnosis of the physician from Gratz, he immediately laughs and rejects his ideas, and likewise the General does not trust the validity of the argument, as he himself did not believe in the supernatural.
The General disregarded his advice and read the doctor’s letter on his own. Under any other circumstance he would have laughed at the doctor's words, but his desperation persuaded him to take it seriously. The letter claimed that Bertha was being visited and attacked by a vampire. He was skeptical of the existence of such a creature, but was willing to act upon the doctor’s instructions.
It is only his desperation to save his niece that convinces the General to listen to the physician’s advice. Although he did not believe in the existence of the vampire, he was convinced to act out of love for Bertha. Pure, familial love is therefore the motivator for defeating the evil and supernatural Carmilla.
That night, he hid himself in Bertha’s dressing room as she fell asleep. Around one in the morning, he witnessed a large black object crawl into Bertha’s bed and attack her throat. The General leapt at the creature with his sword, and the creature suddenly transformed into Millarca. He struck her with his sword but she was unaffected and she disappeared. Bertha died by the morning.
Although the General does realize the truth about Millarca/Carmilla, he is unable to save Bertha in time. Carmilla succeeds in stealing Bertha’s innocence, and she kills the General’s beloved niece.
With the General’s story completed, Laura and her father are unsure of what to say. Her father enters a chapel while the General dries his tears. Laura is relieved to hear Carmilla and Madame Perrodon, although they don’t appear. Laura contemplates the story she has just heard, observing her decayed and destroyed surroundings, and a feeling of horror settles within her. She is worried that her friends are about to walk into danger.
After hearing the General’s story, Laura and her father still don’t suspect the truth about Carmilla. Nonetheless, Laura begins to truly become afraid that her friends are in real danger, even though she can’t conceive that Carmilla is the reason for that danger.
Carmilla enters the chapel. Laura rises to greet her but is interrupted by a cry from the General, who rushes at her with a hatchet. Carmilla avoids his attack, catching his wrist and forcing him to release the weapon. By the time he recovers, Carmilla has disappeared. Madame Perrodon appears and asks where Carmilla has gone, as she had been standing by the door and had not seen Carmilla exit. She goes to search for Carmilla, while the General informs Laura that Carmilla and Mircalla are the same person. He orders Laura to leave the grounds and depart for the clergyman’s house until they fetch her. He says that she will never see Carmilla again.
This is the moment in which Carmilla’s true identity becomes clear, as the General finally sees her and tells Laura that Carmilla and Mircalla are the same person. Now confronted with the reality of her friend, Laura must face the true nature of the world and the girl she thought she knew.