In 1990, a huge spacecraft appeared above the earth. People were panicked but curious. After a period of intense waiting, the alien spacecraft remained silent. Humanity finally approached it carefully and forcibly entered the cabin. As a result, countless aliens were discovered. They described them as ugly, like shrimps, and in extremely poor health and weakness. It turned out that this was a group of refugees from extraterrestrials. They were eventually accepted by the people of Earth and lived in isolation in an area in Johannesburg, South Africa, called the "Ninth Area". After 20 years of reproduction, the number of alien refugees has expanded to as many as 1.8 million, and conflicts with surrounding humans continue. More and more humans are calling for the "prawns" to be driven out of the earth. After consultation, MNU (Alliance of Nations) decided to move the alien refugees to more remote areas. Special agent Wikus (Sharlto Copley) of MNU's extraterrestrial affairs department is responsible for the relocation. Wikus was arrogant and casual during the mobilization process and frequently clashed with local residents. In the end, he paid the price for his actions. The mysterious fluid of the alien infected him, and Wikus slowly transformed into an alien...