Tomorrow When the War Began is a young adult novel which tells the story of Ellie Linton and her group of ragtag teenage friends. The group, which had gone out to the bush of Australia to camp, returns one day to their town to find people disappeared and animals dead. Distressed, the group quickly discovers that their town has been taken over by an unidentified military force so that it could be used as a beachhead for their invasion. That force, which Ellie and her group saw and heard flying over them while camping in the bush, was never identified.
Marsden says that he did this intentionally; the detail is also important because of when the novel was written and published, America and its allies were still reeling from the effects of the Cold War with Russia and concerned about potential invasion or nuclear attack (ideas which were echoed in other works, like Red Dawn). During that time, no one knew who danger would come from. Would it be from Russia, or another unaffiliated country? Marsden's choice to not name the invaders is reflective of the fear of the unknown of the people living in that time period.
While intelligent and resourceful (not many adults could camp in the Australian bush), Ellie and her friends are children. So, when they are faced with an adversary that is determined to conquer the rest of Australia, which they see as a place to mine, Ellie and her group ultimately decide to go face-to-face with the occupying force and try to drive them out. First, they must rescue several of their group members who have gone missing, something which they successfully do.
Eventually, after seemingly constant trials and tribulations, Ellie and her group successfully manage to destroy the bridge that would have allowed the occupying force an easier route into the rest of the country. But that victory does not come without a cost: the lives of two of their friends.
Tomorrow When the War Began is reflective of the time period in which it was written. It is a novel firmly rooted in history and popular culture. First and foremost, it is a novel meant to entertain its readers. While it has many important and complex themes (like dealing with violence and trauma at a young age and making the best out of a bad situation), the novel has little academic value. Ultimately, Marsden's novel is about friendship, banding together to accomplish a goal which would be impossible alone, and using limited resources to accomplish a very difficult goal.
