In Part IV, the Mariner's soul is "in agony" (line 32). He views himself as unworthy to count himself among humankind, calling the men who died "so beautiful" (line 33), while comparing himself to "the thousand thousand slimy things" that, like him, live on (lines 34-35). He expresses his remorse by trying to pray, but finds that he cannot because his heart is "dry as dust" (line 44). Because he has killed the albatross, the mariner has cut himself off from the natural world; he is disconnected from life; his spirit is dead. In his suffering, he wishes he would die, but he cannot even do that. He is doomed to endure the "curse in a dead man's eye" for "seven days and seven nights" (lines 57-58).
At the end of this period of unrelenting suffering, the Mariner is granted a reprieve of sorts. As he stands alone on the ship and watches the water-snakes swimming in the moonlight, he is struck by their beauty. He describes their movements and colors and says,
"O happy living things! No tongue
Their beauty might declare:
A spring of love gushed from my heart,
And I blessed them unaware" (lines 271-82).
Through his heartfelt appreciation of the natural world, the Mariner's isolation is relieved. The albatross falls off his neck into the sea, and the Mariner, reborn, finds he can pray again.
In Part IV of The Rime of the Ancient Mariner, the Mariner continues to detain the wedding-guest in order to relate his tale to him further. The guest fears that the Mariner is a ghost, but the Mariner assures him he is alive as he continues to describe the southbound voyage to the Antarctic.
The Mariner describes his efforts to pray as, surrounded by all the dead, he looks to heaven and wishes a prayer for him would issue forth. But he is unable to pray because the dead sailors at his feet, whose bodies have somehow not begun to rot--"Nor rot nor reek did they" (l. 254)--seem to stare at him and curse him with their "dead man's eye(s)" (l.260).
However, after the religiously significant seven days and seven nights of enduring the curse of the dead, the Mariner beholds others of God's creatures by the light of the moon. Although they are formidable eels whose electricity can be deadly, the Mariner sees beauty in them:
Within the shadow of the ship
I watched their rich attire:
Blue, glossy green, and velvet black,
They coiled and swam, and every track
Was a flash of golden fire.... (ll.277-281)
Rather than perceiving the creatures of nature as something to destroy as he has done with the albatross, the Mariner now sees beauty in God's creation, even in so formidable a creature as the eel, and he is redeemed. After this insight, the Mariner observes, "The self-same moment I could pray" (l.289). Then the albatross falls from his neck, and he is reborn in faith.