I am Number Four

(source: http://www.bookrags.com/studyguide-i-am-number-four/#gsc.tab=0)

I am Number Four by Pittacus Lore is a novel that takes a look at the consequences of alien contact and survival of the human species. Lorien is a planet that is a hundred times older than Earth. It has already faced the myriad of problems with which Earth is only beginning to struggle now - global warming, food shortages, overpopulation, and pollution are all part of Lorien's history. Twenty five thousand years ago, long before they were able to travel through the universe, their planet began to die. The inhabitants of Lorien knew that something drastic had to be done to ensure their survival. They made a commitment to change their way of life, and slowly do away with the harmful chemicals, bombs, pollutants and guns. In time, the damage began to reverse itself, and Lorien survived. Another planet, Mogadore, faced the same issues, but its inhabitants were less concerned. Instead of making changes to ensure their survival, they continued to use and abuse the planet they called home. They didn't understand that their waste and sewage would kill their rivers and lakes. They failed to comprehend that this would cause the herbivores to perish and that the carnivores would soon follow. Instead, they used their resources up, and then traveled to the next closest life-sustaining planet - Lorien. The battle was fierce and the Lorien citizens fought valiantly, but failed to save their planet from the Mogadorian invasion. Six children were sent into space with their Cêpans on a year long journey to Earth. Once there, they separated, each protected by a Loric charm. They had to survive until they came into their Legacies and became powerful enough to return to Lorien and reclaim their home. Their Cêpans were tasked with their education and their safety and as long as they remained apart from each other, the Lorien children known as the Garde could only be killed in specific order. As an added