Note: A long narrative poem in three books. First published in The Wanderings of Oisin and Other Poems, 1889.

Synopsis: The poem is in the form of a dialogue between the Fenian warrior-poet Oisín and St. Patrick. Oisín tells about the three hundred years he spent living among the Sidhe after one of them, Niamh, fell in love with him. He visited enchanted islands, fought a demon, and feasted with the Sidhe, then wanted to return to Ireland and see his former comrades. Niamh warned him that if he touched the ground there he would die. He found his comrades dead and Ireland converted to Christianity. After falling from his horse, he became very old; he spoke with St. Patrick, discussing the differences in their times and worldviews, and then died.