The narrator Egaeus, a studious young man, grows up in a large, gloomy mansion with his cousin Berenice. He suffers from a type of obsessive disorder, a monomania that makes him fixate on objects. Originally beautiful, Berenice suffers from an unspecified degenerative illness, of which periods of catalepsy, are a symptom, which he refers to as a "trance". Nevertheless, they are due to be married.
One afternoon, Egaeus sees Berenice as he sits in the library. When she smiles, he focuses on her teeth. His obsession grips him, and for days he drifts in and out of awareness, constantly thinking about her teeth. He imagines himself holding the teeth and turning them over to examine them from all angles. At one point, a servant tells him that Berenice has died and shall be buried. When he next becomes aware, with an inexplicable terror, he finds a lamp and a small box in front of him. Another servant enters, reporting that a grave has been violated, and a shrouded disfigured body found, still alive. Egaeus finds that his clothes are covered in mud and blood, and he opens the box to find that it contains dental instruments and "thirty-two small, white and ivory-looking substances": Berenice's teeth.
The Latin epigraph, "Dicebant mihi sodales si sepulchrum amicae visitarem, curas meas aliquantulum fore levatas" at the head of the text may be translated as: "My companions said to me, if I would visit the grave of my friend, I might somewhat alleviate my worries."[ This quotation is also seen by Egaeus in an open book towards the end of the story.
