In Edgar Allan Poe's groundbreaking short story "The Tell-Tale Heart," there are two moods that are consistently present throughout the narrative: paranoia and claustrophobia.
The story is told from the perspective of a man experiencing hallucinations that stem from psychosis. He is paranoid about the world around him, especially the old man who lives with him. The narrator believes the old man possess the "evil eye" and that the narrator must kill the old man in order to eliminate the evil eye.
The evil eye itself causes a sort of claustrophobia for the narrator. In the narrator's view, the evil eye is akin to a radioactive material that causes negative effects. The fact that the possessor of the evil eye is his housemate makes the claustrophobic mood more palpable due to the close proximity of the old man.
This feeling of suffocation can be seen in this excerpt:
I made up my mind to take the life of the old man, and thus rid myself of the eye forever.
The claustrophobia and his increasing paranoia were so intense that liberation could only be attained through murder. Another excerpt that shows the narrator's paranoia is this:
They heard! – they suspected! – they knew! – they were making a mockery of my horror!