Roadside Picnic – Read the short story here.
http://www.cca.org/cm/picnic.pdf
The aliens came in the Night. Some people saw them but became ill and quickly perished; others heard them and still bear the scars, both physical and mental. Others, the Survivors, only know what they have pieced together from the fables of the deranged and the evidence left behind in the Zones. A Zone is recognized by the United Nations as a region where an alien vessel landed. It may seem at first glance to be an old shipping yard, a barren park, or a run down neighborhood, but it hides many deadly secrets. The strange radiation of the alien spacecraft transformed the plants, insects, and animals, even people, which were in close proximity. The Zone is a deadly place of quarantine, no one but UN authorized Scientists are allowed to enter the Zone. Trespassers are shot on sight by elite Military operatives. In the new Frontier towns surrounding a Zone, a black market has formed, based on the trade of alien technology recovered from the Zone. Smugglers are called Stalkers, and they take their job seriously. The town of ACville is a Class I Zone. You find yourself stuck here, unable to afford the cost of relocating, and the town is dying in poverty and disease.