Tale by Poe, published in the Southern Literary Messenger (1835) and reprinted in Tales of the Grotesque and Arabesque (1840).
Egaeus, gloomy and unhealthy, grows up with his cousin Berenice, who is “agile … overflowing with energy” until she contracts a form of epilepsy that causes frequent trances. The youth's mind becomes diseased, and although he never loved Berenice while she was normal, he now madly proposes marriage. As the wedding approaches, he sees her as she is, pale and shrunken, but her white teeth fascinate him, and he feels insanely certain that to possess them would cure his own malady. When she is stricken with epilepsy and entombed as dead, Egaeus, unconscious of what he does, draws her teeth. He returns to the library, and there a servant makes him aware of what he has done, telling him that Berenice has not been dead but in a trance.