Welcome to Canine City, or formally known as Ravis city. About 30 years ago, there was a major viral outbreak. The humans were evacuated , they left everything they knew behind. The governement denied that the city even existed. To keep anyone from looking and searching, they built a 300 story high wall around it, quarentining the city. No one gets in and no one gets out. But alas, there is life here. The canines are ruling. The humans will never be able to return to the city they once inhabited, being the virus has pretty much remained, even after the government has dropped a few antibiotics into the city, via helicopter. The canines had also become immune to every type of antibiotic. The government has now left the city be. Basically, according to them, it doesnt even exist anymore.. It was wiped off the map. But what's more, a train carrying toxic chemicals derailed and spilled its cargo.