They arrived in a spacecraft over Johannesburg in 1982, hovering above the South African city like a portent of the unknown. When government-instructed military officials finally entered the UFO to investigate, what they found was an alien race, later labeled "prawns" by the human citizens and media, who were frightened, starving, and hopelessly stranded in a place as foreign to them as they were to us. Marginalized by a xenophobic society—there are also stirring parallels to apartheid racism—the intergalactic beings were sectioned off in District 9 amidst a chained-in landscape of slums, shacks and demoralizing squalor. Reasonably benign creatures with the capability of base modes of defense when threatened, their weapons remain an enigma to earth-born people who do not have the correct DNA to use them. When Multi National United (MNU) sends Alien Affairs field operative Wikus van der Merwe (Sharlto Copley) into District 9 to evict the inhabitants and move them to a relocation camp, the private company's lack of empathy and utter disregard for the prawns and their homes send out resulting shockwaves throughout the city.

The inventively auspicious directorial debut of Neill Blomkamp, "District 9" confirms what 2008's "Cloverfield" served to prove: the science-fiction genre can break ground and inspire awe without having a nine-figure budget. Made for just $30-million, "District 9" puts recent higher-costing junk like "Wolverine" and "Transformers: Revenge of the Fallen" to shame in every department, exhibiting a one-of-a-kind script, stronger performances, a more cohesive handle on cinematography and editing in relation to the action set-pieces, and far superior and seamless visual effects work. Aided by a narrative approach that moves between that of a documentary and a conventional fiction film, the viewer is left enraptured, believing, if only for the space of the running time, that what they are watching is real. The prawns, looking like a cross between a human, an insect and a crustacean, integrate with the live-action characters and surroundings with a seamlessness that has rarely, if ever, been captured on film with such authenticity. Indeed, bringing these intelligent creatures to life is an astounding step forward in alternating CGI and practical effects technology.

Provocative in its entirety but most enthralling in its setup, "District 9" wastes no time jumping into its central premise of aliens who arrive on Earth and are then left marooned when a part from their ship comes loose and falls off. Writer-director Neill Blomkamp and co-writer Terri Tatchell combine interviews with scientists, doctors, government workers and everyday citizens with archival news footage depicting the plight of the prawns, ill-adapted to their new world and viewed by others as little more than scavenging bottom-feeders. As the story's timeline catches up to the present day and MNU comes knocking in District 9 to evict the residents, the hostility with which the prawns are treated—some are assassinated when they refuse to leave—is horrifyingly captured in an unsentimental fashion by "you-are-there" handheld cameras. The prawns are far from angels themselves, but they are also victims of their own circumstances, unable to get a leg up from a society that would rather sweep them away with the trash, or, in a few fringe cases, devour their body parts as a cockamamie means of gaining their power.

When Wikus is sprayed in the face by a canister of fluid he finds in the home of one prawn, Christopher, it is quickly bagged and sent away. Hoping to not arouse worry, Wikus attempts to hide his contact with the mysterious liquid—that is, until his growing sickness and bodily changes cannot be denied. When one of his hands is revealed to have transformed into a prawn's claw, untrue rumors are unleashed—Wikus' distraught wife Tania (Vanessa Haywood) is told her husband has been engaging in interspecies sex—and the government sees it as their key to finally being able to test the aliens' weaponry. Wikus ultimately escapes capture and goes on the lam. What follows, as Wikus reconnects with Christopher and discovers there might be a way to revert his physical changes, leads to a climax grand in scale and plentiful in death, destruction and firepower.

Despite liberally borrowing from "The Fly," "District 9" dares to be different enough to not seem like a reimagining or a rip-off. Wikus' gradual metamorphosis is his just desserts. Once a big dog at MNU, he is suddenly faced with becoming exactly what he has viewed all along as a lesser life form. A scene where he is forced by his colleagues to use the prawns' deadly weapon on extraterrestrial innocents—he is the only one who can use it, since he now is sharing their DNA—is as uncomfortable and appalling as it should be. The third-act action sequence goes on a little long and strikes the viewer as disappointingly routine in comparison to what has come before, but it is still mounted with skill and coherence, refusing to become just a jumble of explosions, chaos and flying metal. Michael Bay could afford to learn a thing or a thousand from director Neill Blomkamp, who, despite having never made a feature film before, is already infinitely more proficient as a filmmaker.

Majestic and matter-of-fact in equal measure—the shots of helicopters circling the spacecraft, or of it looming large in the background, are visual wonders—"District 9" provides purposefully difficult and uneasy food for thought to go along with its more visceral thrills. While certain questions are never answered—why the prawns came to earth in the first place is not broached—this, in a way, only adds to the lingering mysterious aura of the film. And, if a sequel was ever attempted, at least the viewer can take comfort in knowing that one is naturally set up here without it feeling like a strained or inorganic cash-in. Has there ever been another movie that realistically showed what would happen if aliens and humans had no choice but to coexist with each other? "District 9" is a far cry from "Alien Nation," that's for sure, exposing human nature for all of its prejudices and petty narrow-mindedness. Director Neill Blomkamp asks in the end if we really are any better than the prawns. There is no need to provide an answer; the picture speaks for itself.