The beginning of the 22nd century doesn’t look much like the kind of “midday” in the human history. Earth is overcrowded, science is in crisis, and no way out of the dead end is in sight. It seems that luck smiled on the talented physicist Marat Irsanov—the Great Guests, aliens from the Older Worlds, chose him to take part in important scientific research. At the same time, the visitors carefully protect their secrets: after the contract ends, they erase the memories of those who worked with them. However, after breaking onto a military base of a dead supercivilization, Marat learned much more than a barbarian Earthling is supposed to know…