For the past 20 years an extraterrestrial race has been forced to live as refugees in slum-like conditions after there spaceship made first contact over Johannesburg South Africa. Over time alien and human relations have become extremely tense, leaving the South African government to contract a private company, Multi-National United to deal with relocating the alien race. When a MNU agent becomes infected from alien biotechnology he quickly becomes the most wanted man in District 9.