sentences:  Commander Towers is in communication with the only other remaining active-duty US Navy vessel, another nuclear submarine, USS "Swordfish", on duty in the Atlantic, which, at the end, is based in Montevideo.Melbourne, where much of the novel is set, is the southernmost major city in the world.It will be the last such to die, but people in New Zealand, Tierra del Fuego and other, more southerly points than Australia, are said to have a few additional weeks left to them.