Madeline is Roderick’s twin sister, who at the onset of the story is dying of a mysterious disease. Roderick describes the illness as cataleptic, meaning that Madeline suffers from trances or seizures that render her stiff and unconscious. Madeline is an enigmatic character, whose brief appearances raise many questions and few solid answers. Even the narrator finds her frightening appearance difficult to rationalize away, with the one glimpse he has of her leaving him in awe and fear. While the narrator is generally able to find a logical explanation for most strange events, he calls his reaction to seeing Madeline “unaccountable,” which has led some scholars to believe only the supernatural can explain her apparent illness. After Madeline’s interment, Roderick mentions that “sympathies of a scarcely intelligible nature had always existed between them,” another vague and intriguing description. This ineffable bond between the twins could simply refer to how they both sicken at the same time or explain Roderick’s unwillingness to leave the house. It’s also possible, given the strange, single-branch nature of the Usher lineage, to read this phrase as suggesting an incestuous relationship between the siblings. However one reads their closeness, her illness devastates Roderick.

A reader’s interpretation of Madeline as a character radically changes how one sees Madeline’s escape from the tomb. From the narrator’s perspective, she is a tragically ill woman, and he sees her impending death as a rational explanation for Roderick’s melancholy. Supporting the narrator’s lack of superstition, the very symptoms of Madeline’s illness make her appear dead. Just as a rationalist reading suggests that Roderick’s hypochondria creates his own illness, his fears of his sister’s dying cause him to prematurely believe she has passed. Some scholarship locates Madeline in Gothic archetypes. For example, one popular reading suggests Madeline may be a vampire feeding off Roderick, accounting for the elements of his malady that are similar to anemia such as pallor and exhaustion. Another Gothic reading of Madeline views her as Roderick’s doppelganger or Gothic double. This reading posits that Roderick and Madeline represent a single soul split into mind and body, with Madeline as representative of the body and Roderick as the mind. Thus, Roderick and Madeline share an unbreakable bond, and the death of one hastens the death of the other.