To most people who know him Jonnie Cain is an ordinary twelve year old boy. He is though a twelve year old boy with an extraordinary secret, because Jonnie can transform himself into the space adventurer Jonnie Rocket! He is a quiet, grounded boy, who is confident in a non-arrogant way, but Jonnie has an inbuilt flaw – his impetuosity, which often lands him in trouble. Like many boys of his age he loves to listen to music on his ipod and play computer games. He’s a keen swimmer, plays football and collects model cars (especially American 1950’s models) – but the thing he loves best is riding his bike!