The story is told in the form of witness statements related to a criminal case from the early 18th century. The story's title characters are two physicians named Dr. Abell and Dr. Quinn. They both practice medicine in Islington, which is now a part of London but which would have been a separate small town at the time in which the story takes place. Dr. Abell seems to take an interest in magic and the occult. Dr. Quinn begins to suffer from terrible nightmares. Dr. Abell appears to be implicated in Dr. Quinn's death.