Pretty, intelligent and courageous Yuko Tsuno is an electronics engineer. With her friends Pol and Vic she travels round the globe and through time and space. Vic and Pol were working for a television network when they met Yuko. They quickly became friends, drafted a project and set out to investigate an underground river. They soon find a lot more than they bargained for and become part of a story that began millions of light years away, changing their lives forever.