One Thousand Stars in the Sky

A class come into school on what they thought was an ordinary day at school. But in a life changing moment, they are torn apart, flung across the country in the aftermath of brutal nuclear missiles.
Four years later, most of the population is dead, few have survived the radioactive residue. So when, in a series of miraculous events, the class is slowly reunited, they are left with the burning question:
How are we all still alive?