The animated film tells the heartfelt story of a young Irish boy named Keegan, whose life is touched by loss after the passing of his grandfather, Patrick. Patrick, who was the keeper of a lighthouse, had always warned Keegan that the lighthouse was vital to keeping the huntsman at bay. According to him, should the lighthouse's light fail, the deadly huntsman, portrayed powerfully by [Brendan Gleeson], would hunt down the magical deer that sustained the river and the surrounding land.
As the town celebrates the river through a traditional dance known as Riverdance, Keegan struggles with the weight of his grandfather's legacy. The night Patrick dies, Keegan’s failure to light the lighthouse unleashes the huntsman upon the river, setting off a chain of magical and perilous events. His Spanish friend, Moya, invites him to a secluded waterfall at high noon, where she teaches him the dances that celebrate their homeland.
It is here that Keegan meets two talking deer, Penny and Benny, who are part of an extraordinary herd that preserves the essence of the river through their elaborate dances. The elder deer, also named Patrick, reinforces the significance of Riverdance as the source of life and strength for the land.
Meanwhile, lurking in the river, the huntsman prepares his trap near the main watering hole. Through a series of events, Keegan plays hurling with the deer, scoring a goal and bonding with them. When he accidentally discovers the huntsman's lair, the menacing figure tries to lure him into his world, where he promises a reunion with his lost grandfather. With an unyielding spirit, Keegan refuses, invoking his grandfather's wisdom and caution about trusting the huntsman.
Escaping the lurking dangers, Keegan, along with Moya and the deer, embarks on a journey to the edge of the world, where they meet the gatekeeper, [John Kavanagh]. He divulges the deep connection between Keegan and his grandfather, hinting at dances shared by spirits at the mystical gates.
The huntsman's threat escalates when he captures Benny, the most unassuming of the deer, and demands an exchange involving Patrick's antlers. In a tense encounter, the huntsman shoots Patrick down, causing chaos as the river ceases to flow. Yet, Keegan, fueled by determination, uses his hurling skills to thwart the huntsman and returns the sacred antlers to the river, invoking the spirit of Patrick.
With the spirit rising, glowing brilliantly like a guiding lighthouse, the huntsman is banished, restoring balance. Benny's antlers grow to a magnificent size, and he is crowned the new king of the deer, yet with his newfound glory, he becomes complacent and whimsically decrees that he shall outlaw hurling and early morning dancing in favor of gluttony.
In a touching resolution, Keegan takes on the responsibility of lighting the lighthouse, committing to honor his grandfather's traditions as he returns to the thriving town to celebrate St. Patrick’s Day, forever changed by his adventures in this enchanting tale of loss, love, and the magic of dance.
