In John Marsden's novel of Tomorrow When the War Began (TWTWB) the characters face a number of life threatening situations that force them to change and adapt in order to survive in their new, 'war zone', environment. Once the invasion had started, Homer completely transformed as a person. During school, he had a reputation of being the class clown and the school rebel, but later is recognised as the group leader who uses his quick soldier like thinking to create effective strategies and ideas. Through Ellie's brave actions and change in personality, we learn that she is another character that is forced to change and adapt in order to survive. Characters are not the only things to go through change in this novel. The town of Wirawee is also forced to change and adapt from a quiet, happy place into a war zone. It is difficult to predict the outcomes that change will bring and how someone or something changes in order to survive.
The theme of change and adaptation is evident in the character of Homer, as he has completely changed both his attitude and everyday actions to suit the situation and environment he finds himself in. At the beginning of the novel, we learn about Homer's immature behavior at school and how he was irresponsible, untrustworthy and had a reputation of being the class clown. Ellie described Homer as being, 'wild and outrageous. He didn't care what he did or what anyone thought'. Homer gradually displays more maturity throughout the course of the novel and begins to display excellent leadership qualities, which help him develop into the leader and commander of the group. Ellie said, 'it's hard to think that this fast thinking guy was once hardly even trusted to hand out the books at school'. This demonstrates the transformation of Homer and also shows that the other characters are aware of his development of character. What makes Homer such a remarkable leader is his, 'ability to put himself into the minds of the soldiers, to think their thoughts and see through their eyes'.