On the outskirts of space developed by mankind, a star exploded. People died. This is a catastrophe. And in a neighboring system, a person died at a little-known station. Is this an accident?.. To figure it out, intergalactic detectives urgently fly to the scene, whose methods of investigation, however, have changed little since the days of Sherlock Holmes.

While exploring the next systems, space reconnaissance accidentally stumbled upon a space-time anomaly — the most ordinary people lived on one of the planets... in the era of the European Middle Ages. Although stunned by such a discovery, the earthlings nevertheless made contact... But they killed the heir to the throne, and in order to justify the aliens in the eyes of the superstitious inhabitants of the medieval planet, intergalactic detectives begin the investigation.