A young woman, named Aileen moves to a dance academy with her three cousins, Ferris, Fiona and Ciar in Dublin. The cousins involve themselves in new experiences, for they grew up in a remote part of Ireland. As they settle into their lives, the people around them see that the four cousins are beyond naturally gifted dancers. They move in elegance, grace, mystery and divine beauty like swans. Some of their classmates become enthralled with their exquisiteness, dance and supernatural attributes that spellbound them in different ways.

Aileen gets caught up in her new-found life, finding love and her swan song. Each one of the cousins have a secret hiding away from another. Aileen's love life becomes a division that soon circulates to a chain of events that connects each one of her cousin's down a different path. Aileen follows her swan song and it brings her to choose between two men, she has fallen for. At the same time, a deep-rooted darkness from her family's ancient past about their origins soon befalls them and creates a dark swan amongst them. Now the light and dark must come out in a special dance to save or destroy the family from within and the love that is found.