The film tells the story of two childhood friends, a poor fisherman, Pete Quilliam, and a lawyer, Philip Christian. Pete is in love with Kate, but when her father, Old Caesar, refuses to consent to their marriage, Pete sets off for Africa to make his fortune, asking Philip to take care of Kate until he returns.
In his absence, Kate and Philip fall in love. When news reaches them that Pete was killed, they begin planning their lives together, as Philip prepares to assume the position of Deemster, the island's chief magistrate. The news is false however, and Pete returns to the island a wealthy man. Old Caesar agrees to let Kate marry him, and neither she nor Philip have it in them to break Pete's heart. As the wedding party proceeds in an old mill, Old Caesar sternly warns the newlyweds to remember how serious the vows of marriage are.