the raven by edger allen poe

In "The Raven," the speaker's emotional state heightens as he becomes more and more engrossed in self-torture as he is agitated by the raven's persistence in perching upon the bust and its haunting repetition of the harrowing word, "Nevermore."  This word finds immediate echo in the melancholy heart of the man who has recently lost his beloved Lenore. 

In writing about his poem, Poe remarks,

It will be observed that the words 'from out my heart' involve the first metaphorical expression in the poem.  They, with the answer 'Nevermore,' dispose the mind to seek a moral in all that has been previously narrated.

While at first the narrator believes that the bird has been sent by angels to offer him respite in his grief, the repetition of the single word brings with it a torment of remembrance that overtakes the speaker as until he believes that the bird "or fiend" has come from a tempest "and the Night's Plutonian shore!"  He begs the raven to

...quit the bust above my door!/Take thy beak from out my heart, and take thy form from off my door!

Then, when the raven says "Nevermore," a new connotation of this word enters the speaker's mind.  Despairing of any relief from his grief, he says,

And my soul from out that shadow that lies floating on the floor/Shall be lifted--nevermore!