In Johnny Test, Johnny tampers with Susan and Mary's "Real Life Simulator" machine, inadvertently allowing Mr. Wacko access to the machine, who uses it to turn the town of Porkbelly into a Medieval city! If that weren't enough, Brain Freezer is holding the twins' beloved Gil Nexdor hostage! Johnny and Dukey will push all the limits with numerous laboratory gadgets trying to fix this experiment gone wrong. They will have to break some rules in order to stop the bad guys and save Porkbelly ? all before his parents find out.