Tomorrow, When the War Began

by John Marsden
Lexile:  850
Genre:  Dystopia, Science Fiction

Ellie and her friends have finally persuaded her parents to let them go camping alone.  They have a great time out in the Australian wilderness until they return and find that everyone is gone.  The electricity is off, the phones don't work, and there is no sign of life anywhere.  But then strange aircraft and helicopters are flying overhead.  After some investigating, they find out that the world as they know it has ended.  Their country has been invaded and their friends and family are all being held hostage.  They have two choices:  return to the wilderness and try to survive on their own or stay and try to figure out where everyone went.