A school field trip to an ancient castle goes terribly wrong for a group of friends, when a dangerous storm erupts. As they are about to leave the castle, four friends are cornered by their arch nemesis— the class bully, who tries to pull one of his usual pranks. Instead, they all get the scare of their lives, when they fall down a tunnel that transports them into the future: a future where mankind has nearly disappeared from the face of the earth, and where nature has taken control. The friends will have to face up to this hostile new world— as well as their nemesis, who must come to terms with his own trauma— if they are to work together and have any chance of making it back home...