In 1990, a massive star ship bearing a bedraggled alien population, nicknamed "The Prawns," appeared over Johannesburg, South Africa. Twenty years later, the initial welcome by the human population has faded. The refugee camp where the aliens were located has deteriorated into a militarized ghetto called District 9, where they are confined and exploited in squalor. In 2010, the munitions corporation, Multi-National United, is contracted to forcibly evict the population with operative Wikus van der Merwe in charge. In this operation, Wikus is exposed to a strange alien chemical and must rely on the help of his only two new 'Prawn' friends.

Dr. Adrian Helmsley, part of a worldwide geophysical team investigating the effect on the earth of radiation from unprecedented solar storms, learns that the earths core is heating up. He warns U.S. President Thomas Wilson that the crust of the earth is becoming unstable and that without proper preparations for saving a fraction of the worlds population, the entire race is doomed. Meanwhile, writer Jackson Curtis stumbles on the same information. While the world s leaders race to build arks to escape the impending cataclysm, Curtis struggles to find a way to save his family. Meanwhile, volcanic eruptions and earthquakes of unprecedented strength wreak havoc around the world.