A giant spaceship hovers over a world capital, just as in The Day the Earth Stood Still. Only this time it’s Johannesburg, not Washington. And the beings that emerge aren’t elegant, superior dudes like Michael Rennie and Keanu Reeves; they’re large, icky insect types, with wriggling worms where their noses might be. Nor do they issue the lofty proclamation that the peoples of the world must resolve to live in peace (or we’ll all be killed). Instead, these space things, more than a million of them, hang around for 20 years in a ratty part of Joburg called District 9 while their vehicle awaits the spare parts it needs to make the trip home.

By now, most earthlings are less afraid than annoyed; they see the illegal aliens as just another class of lowlife troublemakers. Because they also look like creepy crustaceans, they are slapped with the derisive term prawns. They possess weapons no human can fire, but a gang of Nigerian thugs buys up most of the stash anyway, while supplying the creatures with women who’ll engage in interspecies prostitution. When local resentment reaches its boiling point, a private firm gets a government contract to cattle-herd the furriners to a new settlement, far from the city. To enforce this transgalactic apartheid, the head of the company calls on his naive, underachieving but very game son-in-law Wikus (Sharlto Copley)…

In this monster movie, the monster is us.