So I saw this movie yesterday. My reactions? I was impressed. It really demonstrates the horrific things that humanity is capable of. It's a very emotional film, with some of the aliens even having children.
Basically, for a short synopsis: The aliens come to Earth (for whatever reason) and are stranded. The mothership that you've probably all seen in the ads hovers above Johannesburg for two months with no contact, so the humans decide that they'd better cut their way in. There, they find around 1.8 million aliens, huddled up for warmth, malnourished and sick. So they evacuated them from the ship, and put them in their own camp in Johannesburg, which was guarded by the military. This was meant to temporary, but fairly soon, the aliens had set up a whole slum in there, making shacks and so on. This became their permanent residence, and was named "District 9".
MNU was the private agency hired to take care of the aliens, evacuating them from the mothership and so on. They're responsible for guarding them, and killing them if they pose any threat to any human being. MNU has it's own, private army.
The movie follows Wikus van de Merwe, an MNU operative who is responsible of serving all of the aliens with eviction notices, because they're going to be moved away from District 9, into the new "District 10", which is more like a concentration camp. However, some strange things happen along the way, with Wikus not sure who's side he's on anymore. Through this, he witnesses some of the horrors that humanity is truly capable of.
Basically, he is sprayed with some alien fluid, which begins turning him into an alien. He grows one alien arm in place of his other one, which allows him to operate alien weaponry, because only organisms with alien DNA can operate the alien weapons. Because of this, he is captured by MNU. They take him down to laboratories and experiment on him, and use him to test the alien weapons. He is forced to shoot a variety of different targets, and then a living target, an alien, is brought onto the range. Wikus refuses to shoot this, sobbing, not being able to control himself. However, they strap him to the weapon and induce an electrical shock in his arm, forcing him to pull the trigger and kill the innocent alien.
In the next scene, Wikus is on a dissection table. The decision is made to strip the flesh from his bones and harvest his organs, to try and gain a better understanding of how the aliens work. Using his new found alien strength, however, he escapes, and returns to District 9. He befriends one of the aliens who he tried to evict. It was the more intelligent one. He had a son, and is clearly more intelligent as when he was being evicted, he demanded that his rights be upheld and that he be given 24 hours notice of his eviction.
Basically, underneath his shack is the module that is preventing the mothership from being able to take off. He is planning to fly it up there and escape, and after 20 years, he finally has the fluid he needs to be able to do it. However, it is the same fluid that Wikus was sprayed with, and he confiscated it. MNU has it, four stories underground.
So a retrieval plan is put into action. Wikus approaches the local Nigerian warlord for some weapons, as he has both human weapons and alien weapons. However, they can't operate the alien ones. The warlord has been told by his witch doctors that if they consume (eat) enough of the aliens' body parts, they will gain their power. He prepares to cut off Wikus's arm and eat it. However, he picks up one of the alien weapons off the rack behind him and uses it to escape, taking the rest of their weapons with them. The alien promises Wikus that if he helps him get the fluid and get back onto the mothership, he will use the medical machines on the mothership to put him right, to make him fully human once more. With this in mind, Wikus agrees.
Wikus and the alien, who's name is Christopher Johnson, break into MNU. Four stories underground, they find the lab where Wikus was experimented on. Christopher stares sadly at all the aliens in the body bags, realising what MNU was truly using his people for: grotesque medical experiments. He remains in this stupor until Wikus reminds him to think of his son, and they both escape from MNU with the fluid, and return to District 9 and the command module underneath his shack. MNU is in pursuit, searching for them. Wikus asks Christopher how long the transformation will take and he says "A little longer than expected... Three years." For the reason that Christopher Johnson felt that he must return to his planet and seek help to bring all of the other aliens home. For this reason, Wikus knocks Christopher out and starts the command module with the help of his son, and begins to fly it up to the mothership. However, MNU is quick to realise what is happening, and they shoot one of its engines off with a missile, rendering it flightless. Wikus is then captured by the Nigerians, who still want to ingest his arm. A battle breaks out between the MNU agents and the Nigerians. Wikus is captured and taken to the warlord, who is ritualistically preparing to consume the body. However, Christopher's son, who is still on board the module, uses one of the computers to remotely activate the robot inside their hut, which kills all of the Nigerians inside the hut, and then proceeds to kill the warlord by shoving an electric charged spike directly into his forehead. Wikus takes control of the robot, and goes to find Christopher Johnson. He rescues Christopher, and asks is there's any possibility that he can fix him before he leaves. Christopher says no, but promises that once he has helped his people, he will return for Wikus and cure him. He and his son get in the module and use it to activate a magnetic beam from the mothership, which draws them up, while Wikus holds off MNU. Christopher parts from Wikus with the words; "Three years! I promise!" and then proceeds to activate the mothership and fly away from Earth.
Wikus is then shown collapsing in the dirt, confronted by an old nemesis of his, one of the leading soldiers at MNU. However, the aliens, who obviously accept him as one of their own, surround the soldier as he's about to shoot Wikus, and tear him apart and eat him.
The movie then finishes, with things showing interviews with experts and so on. One of the MNU agents was incarcerated for exposing their illegal genetic experiments (go figure) and no-one knows where Wikus is. However, his wife says that she found a flower made from metal on her doorstep. Her friends all told her to throw it away, but she wouldn't. The movie then concludes with a shot of an alien fashioning a flower out of metal. Wikus's transformation was complete.
The movie then displays text, saying that Wikus van de Merwe still hasn't been sighted one year after the events, and that all of the aliens were successfully moved to District 10, which turned out to effectively be a concentration camp.