Chief Inspector, 'Sarge' Downs of the Cairns police in Queensland, Australia is drawn into the investigation and coroner's inquest following an explosion of an LPG tanker being hauled by a locomotive to Cairns. The information that is established in the inquest shows that it was not an accident. In searching for the suspect, all of Cairns comes under threat from an unexpected quarter that has major links to the university where his partner Professor Sarah Blake works. The outcome will not be known until the very end.