Hundreds of kids have been kidnapped and put into a stone building. In this stone building, everyone is required to become an assassin. Once they turn eighteen years old they are forced to go out to the world to hunt down people. A boy named Arthur wants to go out and escape, on his journey of trying to escape he encounters friends, Estrid, Elliot, Nohr, and Erik. However, once they find out the truth about the outside world a rain of despair came upon them.