Answer:
An unnamed narrator arrives at the House of Usher, a very creepy mansion owned by his boyhood friend Roderick Usher. Roderick has been sick lately, afflicted by a disease of the mind, and wrote to his friend, our narrator, asking for help. The narrator spends some time admiring the awesomely spooky Usher edifice. While doing so, he explains that Roderick and his sister are the last of the Usher bloodline, and that the family is famous for its dedication to the arts (music, painting, literature, etc.). Eventually, the narrator heads inside to see his friend.
