The narrator
The poet in this case serves as the narrator. Through the lens of mythic poetry, we see this poem. Now, the reader should be careful before calling this a simple love poem; the poet here is a well-suffered man who had lost many people to the horrors of the Black plague, someone who had examined the pains of life in intimate detail. His life of suffering prepares him to see this encounter between the lover and his beloved at the Fountain of Love in full mystic, mythic passion.
The lover
This is a young man who by no fault of his own has been ripped apart from his beloved. This loss is symbolic, and so is the character. In one respect, this character is anyone who has experienced the deep agony of loss and heartbreak, perhaps at the death of a loved one, and the lover is thus archetypal. He wants a reunion with his beloved that is impossible in the waking world around him. But, once he has found the Fountain, he is visited by the god of dreams, and he meets his beloved in his sleep.
Morpheus
This Greek god, Morpheus, is the overlord of all human dreams. When he bestows upon the dreamer a mystic visit from his beloved, he does so with perfect timing, suggests the poem. This makes him an archetypal power, a minister of human fate. In this case, dreams are shown to be mystic and powerful, because it takes a powerful dream to change the lover from his agony to a hopefulness about love.
The beloved
This is a mythic woman whose husband has been rent apart from her by fate. The poet doesn't get to meet her, but he does describe her through the experience shared with him by the lover. The lover sees her in a dream, and although it is a dream within the lover's own soul, the encounter with her teaches that they are united in spirit. Their soul is shared in a mystic way that the body obscures, but which is true nevertheless. The beloved is an archetypal character, similar in nature to Jung's Anima conception.
