In many ways, Roderick Usher is the House of Usher: with his sister, Madeline, dying, Roderick is all that remains of this ancient house. And both local custom and his own beliefs link Roderick the man with the physical house in which the Usher family has long lived, as if they were one and the same. Roderick is an educated man and an intellectual. He reads widely and plays music. However, almost the whole of his existence is consumed by his sorrow over his sister's illness, his own illness, and his resulting mental condition and pervasive fear. His visiting friend (the narrator) finds Roderick tremendously changed by what he has gone through. He's very pale, and his eyes shine brightly. He's very thin, and his hair is wild. Because of his condition, Roderick is extremely sensitive to external stimuli, which limits what he can eat, hear, see, and smell without pain. Though Roderick is "onstage" throughout the story and Madeline largely isn't, Roderick as a character is bound to Madeline. As twins, they were born together. As adult siblings, they live together. As people who are functionally two parts of a single whole self, they also sicken and ultimately die together.
The narrator says little directly about himself or his character. He doesn't share where he came from, what his own family life was like, or even his name. However, his thoughts, his conversation, and his actions tell readers a great deal about him. He and Roderick were friends when they were boys but haven't been close since. Despite this distance, he cares enough to travel to visit Roderick at his family home. He is at ease with a wide range of books and music. He also experiences the world through an abstracted lens. This can be seen in the story's opening paragraphs, when he tries to see the landscape around the house of Usher in terms of the sublime. The narrator's concern for Roderick is evident throughout the story, from the fact that he visits, to how he takes on some of Roderick's nervous condition, and how he tries to care for Roderick as his condition worsens.
Madeline barely exists in the story except in two ways: as Roderick's sister and double, and as the embodiment of illness. Her doctors don't know what is wrong with her, only that she is wasting away and is subject to fits of catalepsy, when she becomes completely rigid and doesn't respond to the outside world at all. At those moments it is like she is already dead. When she isn't suffering one of these spells, Madeline is barely more life-like: she drifts from place to place without speaking to people or seeming to see them, as if she were a ghost. Madeline's major appearance in the story occurs after she seems to have died. She is buried alive and then comes back covered with blood, having clawed her way out of her tomb. She embraces her brother, and they die together as the house collapses.