Elementary Science 101

For decades an unknown battle has been going on between destructive invaders from space, and benevolent protectors placed on earth by mysterious beings millions of years ago. The invaders inhabit living creatures to bring about their agenda of destruction and death. Through the use of war, violent attacks, and now natural disasters, they have brought the Human Race to the brink of disaster. Ironically, all Humans are unaware they are even under attack by these outside forces. All except one...