Walpurgis Night. Ex-commissioner Max Raintaler is visiting Machtlfing with friends for the May dance. Franz Wurmdobler, Max's former colleague at the Munich police, draws the others' attention to a supposed UFO in the starry sky at a late hour. Later that same night, a fatal accident occurs. Or was it a brutal murder? As Max seeks to uncover more, he stumbles upon another corpse. Were the aliens involved? An exciting chase for criminals begins in and around Munich...