A thrilling historical adventure inspired by the life of Gráinne Mhaol, the infamous Irish sea captain and folk heroine who risked everything to protect her people against the powerful Elizabethan regime.

Gráinne Mhaol was born to be at sea. Raised alongside her brother by their father, chief of the clan Mhaol, Gráinne learns early that her dreams of the open water are not compatible with the life she's expected to lead as the daughter of a noble family. And when her father marries her to the wrong man, a neighbouring chief named Donhal, Gráinne's world shifts for the worse.

Undaunted, Gráinne raises a family without abandoning her passion, aiding her hot-tempered husband in his campaigns against rival tribes. Eventually ousted from her husband's land in the wake of his death, Gráinne returns to her childhood home and begins her career as a pirate in earnest, claiming new territories and finding deeper love, only to see her livelihood threatened by English incursions into Ireland.