In Skylark Three, when the DuQuesne are attacked by the hitherto-unseen natives of a planet called 'Fenachrone,' a character called Seaton destroys the Fenachrone battleship and captures a crew-member who tells Seaton the Fenachrone's plans to conquest the Universe.
Near the Green System, they are attacked by the hitherto-unseen natives of the planet 'Fenachrone', whose weaponry surpasses any known to Seaton or the Osnomians. Having used the 'zone of force' at first to conceal himself, and then to destroy the Fenachrone battleship, Seaton captures a leading crew-member, who reveals (upon interrogation) that the Fenachrone intend conquest of the entire Milky Way Galaxy, and eventually of the Universe, and that a message is already in progress toward the Fenachrone capital to summon aid. 
