Jim Button is a little black boy living on the tiny island of Lummerland. When Jim grows bigger, there is simply no longer enough space for everybody. Someone has to go, decides King Alfons the Quarter-to-Twelfth. But should that someone really be Emma, the locomotive of Jim’s best friend Luke? Jim cannot allow that. Together with the engine driver and Emma he leaves the island and sets off on the great adventure: Transparent trees, stripy mountains, apparent giants and dragons cross their way. In the end, however, Jim is not only able to solve the enigma of his birth; he also manages to free the beautiful princess Li Si. And even for their return to Lummerland a solution is found.