The relentlessly fast-paced District 9 is a science-fiction fantasy that revolves around a group of human-sized insect aliens whose spaceship has been hovering over Johannesburg, South Africa, for two decades.

Taken from the spacecraft by the humans in what was at first a rescue mission because they were malnourished, they were settled into a walled ghetto which has grown to 1.8 million strong and has become a slum. They have begun to create havoc in Johannesburg itself, with thefts and rioting in the streets. And so the disgruntled humans, who dismissively call the aliens “prawns,” want them moved far away.

But District 9 is no ordinary sci-fi fantasy. That it is set in Johannesburg opens all sorts of social conscience questions since the plot parallels that nation’s apartheid system that for decades separated whites from blacks. Blacks were not allowed by the repressive government to live in the city, but were settled in large slums, such as the notorious Soweto. That the film was made by South African-born Neill Blomkamp, who now lives in Vancouver, Canada, underlines the film’s ties to real life.

Yet District 9 is far from some social-studies lesson movie. It’s rampaging as it moves, moves, moves with lots of hand-held camera work and invented news footage that makes it very vibrant, very much looking like a documentary. The special effects are jaw-droppingly amazing, especially those that make the ultra-slim-waisted aliens with their gesticulating insect heads seem so unnervingly realistic. This is not a movie for the squeamish and certainly not for children, although I’m not sure most adults would call it entertainment in the traditional Hollywood sense.

At its center is a sort of Everyman with the unlikely name of Wikus Van de Mewre (Sharlto Copley). A bureaucrat in the MNU Department of Alien Affairs, Wikus (the “W” is pronounced as though it were a “V”) is promoted (by his father-in-law) to lead the eviction of the aliens to a new tent city surrounded by barbed wire far from Johannesburg.

Wikus naïvely approaches his new job with confidence, pride and unmistakable cheerful enthusiasm. What he hasn’t counted on is that he begins growing sympathetic to the plight of the prawns, who dress in rags and subsist mainly on canned cat food parceled out for a dear price by the Nigerian gangsters who run roughshod over them. Nor has he counted on the resistance put up by the aliens against moving them from their slum to a government tent city that is really a concentration camp. (Here District 9 begins working on more than one level and not just in relation to South African apartheid, but to man’s inhumanity to man in general, everything from Nazi concentration camps to the Israeli walls put up in response to Palestinian unrest.)

One of the dread secrets of the Nigerian overlord is that his comrades have taken to cannibalizing the prawns in hopes of gaining their superhuman powers. One of the dread secrets of the MNU is its secret bio-lab which slices up captured prawns in the pursuit of genetic engineering, something Wikus discovers during his nightmare odyssey.

In the middle of his eviction operation, Wikus unwittingly snatches a small container containing a black fluid in a secret shed. Christopher, one of the technologically adept prawns, plans to use the fluid to power an underground flying machine that will take him back to his hovering spaceship and allow him to fly back to his home planet for the rescue of his kind who are trapped on Earth.

But the black fluid spills on Wikus and, to his horror, he begins turning into one of the insect aliens. Brought back to MNU headquarters, he finds himself about to be dissected by scientists there to gain the incredible genetic properties now flooding his body which, among other things, allow him to fire the complex alien weapons that no human has yet been able to figure out.

Rapidly District 9 turns into an exciting man-on-the-run (or is it half-man-half-insect on the run?) movie as the desperate Wikus tries to save himself, to flee the mercenaries, led by the scarily villainous Koobus Venter (David James), who would bring him back for dissection. Along the way he more or less befriends Christopher, who promises to hold the key to Wikus’ salvation.

The action staged by Blomkamp does not let up. It’s exhausting, although a more judicious sense of editing would have helped. Some sequences, particularly the eviction scenes, go on and on over the same territory. District 9 is nearly two hours long, but seems longer.

Nevertheless, District 9 is a true original, a film that could have been just a throwaway action film. Instead, surprisingly, it becomes a thriller with a conscience, a movie with a message that can spark discussion about how we relate to others, from our neighbors to alien creatures elsewhere in the universe.

****District 9

Starring: Sharlto Copley, David James, Vanessa Haywood.

Rated: R, contains violence, profanity, grisly images.

mjanuson@projo.com