The world is full of zombies and the survivors have barricaded themselves inside a walled city to keep out the living dead. As the wealthy hide out in skyscrapers and chaos rules the streets, the rest of the survivors must find a way to stop the evolving zombies from breaking into the city.

A group of high-school friends must come to terms with the fact that one of them, Samson, killed another, Jamie. Faced with the brutality of death, each must decide whether to turn their friend in to the police, or to help him escape the consequences of his dreadful deed.