It is a cold and wet midnight in December, the Narrator is reading a book of forgotten lore to try and forget his memories of Lenore in his bedroom.
The narrator had heard a tapping at his window so he opened it and a raven flew inside. He thinks the raven can help answer some of his questions.
The raven replies "nevermore" to all of the questions the narrator asks it. This makes the Narrator angry because he is not getting the answers he wants. Therefore, the Narrator concludes, he will never be happy again.