"District 9" is set in an alternate reality where in the 1980's an alien craft appeared suspended in the airspace above Apartheid era Johannesburg, South Africa. Eventually, combined efforts decided to investigate the alien craft which was just in the air doing nothing for a significant amount of time without ever attacking the Earth or attempting to make contact of any kind. When the Earth expedition managed to breach the alien vessel, it discovered a great number of weak, malnourished creatures that brought down to Earth. They called them Prawns and they were at first embraced by the general public.
They were studied extensively by scientists as was their advanced technology for years. It became apparent that only prawns could exactly use their weapons or technology but that didn't stop investigators from working tirelessly to try to crack the secrets of the advanced Prawn tech. A special branch of the government was set up in order to deal with the new Prawn population in Johannesburg and all related issues shortly afterwards. The Prawns were sent to live in a heavily guarded slum called "District 9" that they shared with other displaced African refugees in addition to poor South Africans.
Not too long afterwards, tensions began to rise among the Africans and Prawns due to the fact that they were all displaced peoples sharing a cramped closed off space and they all had to forage, hoard and scavenge to survive. Crime rose and eventually the government agencies stepped in with a solution akin to one they came up with in Cape Town during Apartheid...evict everyone from a certain slum, raze it and then move them. In this case, it was the MNU that would be evicting the Prawns from District 9 and moving them to District 10 instead. Wikus Van Der Merwe is put in charge of serving the Prawn population in District 9 with eviction notices, little did he know how badly that task would go.
The 2 million Prawns that live on Earth after 28 years just end up unorganized and easily exploited overall by the human population. Sure they're an Alien race with advanced technology, knowledge and weaponry but don't forget that they're ass out on a world that is completely foreign to them. The human didn't have to go up there and bring them to their homeworld after all, they could've easily just let them all die on the Mothership instead. Once they're on Earth they are stuck having to do anything they can just to survive from day to day. Much like the poor and displaced Africans they share limited living space with.
Once Mikus begins his job, he realized that it won't be easy and if often met with resistance from some of the Prawn population but after giving them some bribes (including cat food, which seems to not only serve as food for them but a drug as well (?)) they often end up "signing" the eviction notices they're served. Until they come across the home of Prawn Christopher Johnson, his son CJ & on of their associates. While the majority of Prawns are used to being a hive minded colony full of workers, a few of them had advanced intelligence and worked together to try to get off of Earth. Wikus was met with resistance at this home and sprayed himself with a mysterious liquid he found in Chris Johnson's home. He bagged it up as evidence then went about his day.
Shortly afterwards, Wikus began bleeding from the nose, feeling dizzy, vomiting and he feel unconscious at home during a family gathering. Not too long afterwards he begins transforming into a Prawn himself. This means that the MNU takes him against his will and begin testing his physiology in addition to forcing him to use Prawn weapons & technology to further study them. Eventually, Wikus is able to escape the MNU compound and make it back to District 9 to figure out what's happening to him by locating Christopher Johnson.
From there a gang of shit happens as the film switches from a faux Sci Fi documentary into a dramatic Sci Fi action film. Wikus, Christopher Johnson & CJ become embroiled in a plan to reactivate a drop ship, use it to get to the Mothership and get help for the entire Prawn population currently trapped on Earth. Some had issues with the way many Africans were depicted in "District 9" but if you dig deeper into the film you'd see how they could be seen as unfounded. Let me break it down for you...
Essentially, all of the White South Africans in the film that worked for the MNU were exploiting the aliens and the armed military types? Same thing. The only over the top African depictions were gangsters or arms traders that also exploited the Prawns. All of the Black Africans in the film didn't fall into that category, mind you.
This film did have a gang of unanswered questions and people have been debating the finer points of this film for weeks on the IMDb messageboards. Needless to say, I can't wait to go this film of Blu-Ray or see how the sequel shapes up. I have no choice but to give "District 9" an emphatic mos def. Check it out whenever possible.