STANZA 8

11. Plutonian shore - (in addition to the notes listed in the "Foot Note" portion of our site)  The Plutonian shore described in the poem is not truly a place, but rather a metaphor for describing the "hellish" storm which rages outside the narrators window. (Pluto, for those who do not know, was the Roman god of the underworld.)
In reading the next verse we see that the narrator finds it rather amazing that a raven flew unscathed through a torrential storm and marvels still at how the bird happened upon a place where someone was not only home, but willing to let him enter. In taking the metaphor one step further, we can also tell that our narrator is so astonished by the sequence of events that he begins to suspect that the raven's sudden appearance is more than mere coincidence.