25 years previous to the action of the movie, Iolanthe, a fairy, falls in love with the Lord Chancellor. Fairy law states that Iolanthe must die because of it but the Queen of the Faries commutes her sentence to banishment. Iolanthe gives birth to a son, Strephon, who is half a fairy and half a mortal. He falls in love with Phyllis, a ward in chancery who has attracted the affections of the House of Lords and the Lord Chancellor himself. The Lord Chancellor has forbid Strephon to marry Phyllis. However, when the Fairy Queen pardons Iolanthe and promises Strephon her protection, trouble and hilarity ensues!