While vacationing in Corsica, Mr. Barnes of New York witnesses a duel between Paoli and a British naval officer, in which the Corsican is killed. Marina, Paoli's sister, vows a vendetta against the slayer, but the only clue to his identity is the name "Gerard Anstruther" engraved on his pistol. In an art gallery in Paris, Mr. Barnes sees a picture, painted by Marina, of the duel scene, and his interest brings him under suspicion. Barnes later meets Enid Anstruther, an English girl who admires the painting, and he follows her to Nice. There he discovers that Gerard, who is Paoli's murderer, wishes to marry Marina. Her guardian, Count Danella, plots to have Marina wed Gerard, then reveals to her that he is the killer of her brother; Barnes, however, proves that Gerard lent his pistol to a fellow officer who later confessed to the slaying. The count, defeated in his scheme, is killed by Tomasso, who mistakes him for Gerard; and the lovers are happily united.