From the start, the mood of “Berenice” is gloomy and foreboding, especially given the fact that the narrator begins by lamenting the miserable state of the world. This sense of unease grows stronger as Egaeus becomes progressively more unstable, losing track of time and control. The more Egaeus struggles to make sense of his own mind, the deeper the reader’s apprehension grows. Poe incorporates elements of body horror that serve to elongate the tense dread saturating the narrative:
An icy chill ran through my frame; a sense of insufferable anxiety oppressed me; a consuming curiosity pervaded my soul; and sinking back upon the chair, I remained for some time breathless and motionless, with my eyes riveted upon her person. Alas! its emaciation was excessive, and not one vestige of the former being lurked in any single line of the contour. My burning glances at length fell upon the face.
In passages like the above quote, the physicality of the characters in “Berenice” is explicitly rendered to terrifying effect. Egaeus feels “an icy chill,” and in other moments of the story. he repeatedly shudders and pales. Meanwhile, Berenice is so wrecked by her disease that she transforms entirely from a person to an objectified, emaciated body (becoming “it” rather than “she” or “her”).
After the story’s climactic reveal, in which readers learn that Egaeus has violently ripped all 32 teeth from the mouth of the still-alive Berenice, the mood turns to outright horror. The grisly violence that Berenice endures at the hands of the man she loves is strong enough to turn the reader's stomach. Poe ends the story with the final, haunting image of Berenice’s teeth scattered across Egaeus’s library floor, leaving the reader with a profound sense of revulsion and misery.