It’s sheer horror: a lost radio set lies on the ground in the nocturnal forest. You can hear the distant voice of Anthony Perrin, the best friend of German BMX star Bruno Hoffmann. Where did the French disappear to? Bruno Hoffmann launches a search and finds a hint at Berlin’s Teufelsberg (“Devil’s Mountain”). Following the track on his BMX in the dark, he has to overcome several obstacles in order to reach the next level with his tricks, just as in a video game. It turns out that Anthony Perrin is caught in a dark parallel universe.