A merry band of pirates celebrate the coming of age of their apprentice, Frederic. But Frederic has only been a pirate because of his sense of duty. He plans to go to the police and have them arrested. The arrival of Major-General Stanley and his daughters, on a beach outing, changes everything. The police arrive, there is a struggle, bested, the pirates promise to reform. Stanley agrees to let the pirates marry his daughters. Frederic and Mabel are together, at last -- a happy ending.