The Earth-Moon interplanetary route has long been firmly mastered, reliable and stable. Created on the moon and a special Office of Lunar Tourism: an unusual landscape, weak gravity, a view of the Earth, Farside mysteries, a magnificent starry sky, the first settlements. Under Clavius, the first lunar city, even the first lunar park was created, albeit small, but by no means a "window box suffering from megalomania," as "one chatterbox from television" said about it. But the Selena dust engine is a ground-based version of a spacecraft, conducting an excursion, gets into an accident and, surrounded by darkness and silence, plunges into the bowels of the moon...