When the bus pulled up to Highston Academy on that rainy day, nobody on it knew that it would be the last time they would walk into their school. After several schools are hit by mysterious 'terrorists', students all over the country go missing. A new group, called "The Green Siren", appears during the time of the attacks, and assures the country that their children are safe and being looked after. What they don't tell them is that most of their children are unlikely to return home ever again. One group of students manages to get away at first, but they are force to endure life threatening situations, daring escape plans and sheer terror, as their whole life turns upside down. What will happen to them and their friends? And why are The Green Siren kidnapping children? Will they ever find the answers?