In the wake of a deadly SARS outbreak that's turned ordinary folks into flesh-eating zombies, Thailand stands alone as the only nation to block the pandemic. That is, until the virus finds its way into a crowded Bangkok apartment complex.

Mak, a street urchin in Bangkok, dreams of being a tough gangster. He earns some money as a drugs runner. One day he meets a young prostitute, who turns out to live nearby and they fall in love. After he has delivered a large batch of drugs to a rich man on the other side of town, they can suddenly afford new clothes, luxury mobile phones and expensive sunglasses. Made reckless, Mak and his partners use the girl for an even bigger delivery to the same rich man.