Tim Barnabas is a submariner from the Cuttlefish, a coal-fired submarine. Clara Calland is the daughter of a scientist who carries a secret formula that threatens British Imperial power. After a daring chase across the globe, they have brought the secret to Westralia. Here, much of Australia is simply too hot to be habitable by day. People are nocturnal, living underground and working outside at night. To cross the deserts they use burrowing machines known as steam moles. With the Cuttlefish out of action, her crew take jobs on these submarine like craft. Duke Malcolm, of the Imperial Security Service, transports Claras rebel father to a