The townspeople hate Ophelia, daughter of a notorious pirate queen, because they believe she will repeat her mother’s legacy. Ophelia only wants to join the navy to make amends for her mother’s deeds so she steals her sister’s birth certificate to enlist after being barred from joining because of her cursed reputation. But Ophelia soon discovers that a life at sea isn’t as honorable as she hoped. 

When their father falls ill, Ophelia’s half-sister Betsy asks the navy recall her sister, but in doing so reveals Ophelia’s fraudulent enlistment. To save her sister from the naval authorities, she must overcome her anxieties and find her sea legs in a race to find Ophelia before the navy can. 

Between duels, unexpected romance, and lost treasures, the sisters realize that piracy runs in the family after all.