In 1795, on the island of Saint-Malo, Robert Surcouf, a young Frenchman, is denied the hand of his beloved Marie Catherine because her father wants a wealthy son-in-law. Vowing to make a fortune, Surcouf goes to the Île de France and joins the French pirates fighting the British in the Indian Ocean. Although he breaks through the English blockade with a ship bringing food to the starving natives on the island, he receives no recognition since he was not officially authorized for the voyage. Furious, Surcouf sets out for Paris to demand a reward, intending to take Marie Catherine along, but he is attacked on the road and manages to save himself by leaping into the carriage of Margaret Carruthers, a beautiful American woman. He remains with her for a time, but after a duel with her fiancé, Lord Blackwood, Surcouf returns to the Île de France. Later, he learns that Marie Catherine's father is forcing her into a loveless marriage, and he immediately sets sail for Saint-Malo. Arriving in time to stop the wedding, he defeats Marie Catherine's suitor and marries her himself.