It was an end to an all-American school day with nothing exciting happening. All the good little boys and girls boarded their school bus for the ride home, unaware something was changing in the world outside. On board were a motley crew of high school students, your typical assemble of a couple of jocks, a cheerleader, the stuck-up girl, the obese nerd, the Asian goth girl and the loner type good-looking rebel. They never really knew each other before but after that day they would know every little dark and disturbing secret that each one held. Marooned in the countryside with the school bus their only defense against an aggressive flesh-devouring horde of the dead lurking just outside, they must try to work together to survive their ordeal. Isolated with no help in sight, they learn to love and hate their classmates in the intimate ways of lust and blood spent. Their sanctuary a tin meat locker referred to by a mother's nursery rhyme to her daughter which is that of the little yellow school bus.