Alianor O'Hearlihey is the story of a young girl from Ireland on a hero's journey to save her family, friends, and country. When Nicnevin, the evil Queen of Tir na Nog, places a spell on the good Queen Maeve, she commands her to curse all of Ireland to starve its people. Only the Tuatha De warrior Aoife could possibly stop her. But Nicnevin has shattered the warrior's spirit into a thousand shards of glass. Fortunately, one of Aofe's loyal friends, the wily leprechaun Splinters, finds one of the shards and places it into the young body of Alianor in the hopes that it will help reconstitute the warrior.
Alianor is then visited by a spirit, who tricks her into going on a long journey to capture a unicorn. In reality, Alinaor will be on a mission to enter the mystical land of Tir na Nog along with a small band of Tuatha de warriors. Once in that mystical realm, they must find Maeve, capture Nicnevin, make her stand trial in Aos Si, the land of the fairies, in hopes of saving both Tir na Nog and Ireland.