A woman criminal, an air pirate,the Baroness Troixmonde (Filibus) who commits her thefts, etc. and then retreats to the safety of her zeppelin! In a wonderful early feminist plot element, Filibus's "airship is manned by a staff of mask-wearing, black-skin-suit-clad male lackeys who instantly obey the Baroness' every command." The hapless Detective Hardy, puny male that he is, is no match for Filibus!