It's an average day in Phoenix,Arizona.4 classes from Pleasant Valley High will be attending a field trip to RiverZone Amusement Park.All is well,until the bus driver comes to a screeching halt.Everyone gets thrown to different sides of the bus.Sarah gets thrown onto to Tommy,and they share a moment,getting lost in each others eyes,until that moment is interrupted by deafening screams,from both girls and boys. They look up,to see the dead bodies of their former classmates,and bus driver,and a few pale,infected and torn apart bodies shuffling closely to them.They escape the bus,and run back to the school,to only find more of the undead student bodies.They make their way to the Gym,where they stock themselves with weapons.Sarah takes a metal baseball bat,while Tommy takes a wooden one.They go out,pick up some friends on the way,and build an ultimate fortress,and try to survive the Zombie Apocalypse.