As "The Raven" begins, the speaker is "weak and weary" from reading an ancient book. It is "bleak December" and the speaker has been reading to distract himself from his grief over his lost love, Leonore.
When he hears the tapping, he is filled with dread but to calm down, he tells himself it is just some visitor. Opening the door, he finds only darkness, thus increasing the anticipation and tension. He hopelessly calls "Leonore" into the darkness, getting only an eerie echo in return.
When the raven emerges, it flies directly to the bust of Pallas/Athena, creating an odd and forbidding juxtaposition of the dark raven atop the symbol of justice. This puts the speaker in a subservient position. However, at first, the speaker finds some humor (and relief) that his visitor is just a bird. He notes that the raven charmed "my sad fancy into smiling." His humor soon turns to fear, first because the bird speaks and second because his reply is negative. He predicts the raven will leave in the morning, to which the raven replies, "Nevermore."
Now, the speaker, still afraid but still rational, sits down to think about what the bird meant by "Nevermore." He supposes the raven was sent by angels to help him forget Leonore. The raven responds again in the negative, "Nevermore."
At this point, the speaker is so bewildered and distraught that he feeds his own self-torture. He asks if there will be some relief (Gilead - a balm) to his grief, knowing that the bird will reply "nevermore." The speaker again destines himself for more grief by asking if he and Leonore will meet in heaven (Aidenn). In the last stanza, the raven's shadow "overshadows" the speaker's soul, leaving him completely imprisoned in his own grief.
From the speaker's perspective, the entire encounter is, at times, startling, humorous, bewildering, tense, terrifying, and ultimately woeful.