The Dead of Night — John Marsden

Australia has been invaded. Nothing is as it was. Six teenagers are living out their nightmare in the sanctuary of a hidden valley called Hell. Alone, they make their own rules, protect what is theirs, and struggle for courage and hope in a world changed forever. Seeking supplies, allies, and information, the friends make forays into enemy territory, drawing on nerve and resourcefulness they never even knew they had. And as the risks become greater, so too do the sacrifices they must make. The companion to the award-winning novel "Tomorrow, When the War Began".