Centrum. The central world of the universe, surrounded by the petals of other worlds, among which is our Earth. Once Centrum was great and strong, but a catastrophe threw it into the past. Here, at the crossroads of thousands and thousands of civilizations, the Border Guard Corps keeps its watch guards guarding the borders between worlds...An earthling who accidentally finds himself in Centrum has little choice: to become a smuggler or a border guard. And the differences between these professions are sometimes also small... But sooner or later you have to decide what the border service is for you. Because the Earth is threatened by a disaster that once came to Centrum...