Andy, a studious young man, grows up with his cousin Brianna in a large, gloomy mansion. He suffers from a type of obsessive disorder, a monomania that makes him fixate on objects. Beautiful in origin, Brianna suffers from an unspecified degenerative disease, of which periods of induction are a symptom, which she refers to as a "trance". Despite this, they have to get married.
One afternoon, Andy sees Brianna sitting in the library. When she smiles, he focuses on her teeth. His passion grips him, and for several days he flows in and out of awareness, constantly thinking about his teeth. He imagines that he is holding the teeth and rotates them to examine them from all angles. At one point, a servant tells him that Brianna has died and will be buried. When he next wakes up with an inexplicable terror, he finds in front of him a lamp and a small box. Another servant enters, reports that a grave has been breached, and a mutilated mutilated body is found, still alive. Andy discovers that his clothes are covered with mud and blood, and he opens the box to find that it contains dental equipment and "thirty-two small, white and ivory-looking substances": Brianna's teeth.
