Days before the biggest match of her career, an accident sweeps MMA fighter Róisín Ó Ceallaigh into the mythical realm of Tír na nÓg. She's rescued by a mysterious sídhe prince, but gratitude comes with a price. Bound to him by an unbreakable life debt, Róisín is forced to navigate a world of ancient magic, ruthless monsters, political intrigue, and gods who never truly left. She sets out on a journey to recover the legendary Silver Branch, the only artifact rumored to be capable of returning her home. Yet every step deeper into Tír na nÓg reveals long buried secrets, impossible choices, and a destiny that threatens not only her future, but the fate of an entire realm.