This may be a bit chaotic but please bear with me: We start with the immortal "Once upon a midnight dreary", which gives the impression that the narrative takes place at least some while ago. Yet, in the last stanza, the narrator switches to present tense. During the poem, the narrator is haunted both by the memory of his lost love, and the – by his interpretation – demonic presence of the raven. To the narrator, the presence of the raven is immediately connected to Lenore and her untimely death. He also seems both hopeful as well as scared that the visitor could be Lenore. Upon questioning the raven, the narrator is directly told that he will not see Lenore again: "Tell this soul with sorrow laden if [...] It shall clasp a sainted maiden whom the angels name Lenore [...] Quoth the Raven “Nevermore.”" This, as well as the fact that the narrator is visited not by Lenore but by the raven, leads me to believe the narrator is or at least feels somehow at fault for the death of Lenore. The raven in this case represents his guilty conscience, which he can't overcome. The narrator also calls Lenore "a sainted maiden", which I interpret as her having ascended to (some form of) heaven. Upon the realisation that he will not see her again, and not ascend to this same heaven (pointing again to some form of guilt in the matter), he dies, with the raven (his guilt) preventing his soul from rising: "And my soul from out that shadow that lies floating on the floor Shall be lifted—nevermore!" Having switched to the present tense in the end, in my interpretation at least, the narrator tells us about this encounter after his death. There is no way to know how much time passes between the encounter and the narration of it, but to me this is precisely the point. The narrator will forever lie below the raven sitting on the Pallas bust, eternally trapped with and by his guilt.