When a Chinese blockade of Taiwan escalates into a nuclear missile exchange with the USA the aftermath is catastrophic, with a gigantic wave of deadly radiation making its way across the sea towards Australia. The crew of a US Navy submarine, led by commander Dwight Towers place themselves and their vessel under the command of the Australian government and are tasked to track down Julian Osborne, a brilliant yet reclusive scientist who may be able to help out before it is too late.