The Siege at Thorn High.

Edwin promised to his sister on her deathbed to find her son she gave up a long time ago. Edwin's quest brought him to become a substitute teacher in Duri High School, Jakarta, a school for juvenile delinquents. There he must face the most violent students to find his nephew. When he eventually finds the boy, a city-wide riot erupts and Edwin is trapped in the school with the cruel kids out for his blood.