The technologies of future centuries will certainly make it possible to create technically very advanced robots, perhaps even very similar to humans. But whether this robot becomes a friend or an enemy will depend not on its appearance, but on the program embedded in it. This book tells how two robots meet on planet Earth, one of which, Omicron, is programmed to destroy life, and the other, Delta, is programmed to destroy Omicron, which brings death. Delta, a gentle silvery creature capable of feeling the beauty of nature and experiencing physical pain, is most often encountered with the distrust of people, but in the end finds their support, and then love. In the fight against evil, the best qualities of people are revealed: both armchair scientists and seemingly quiet old men show extraordinary courage and ingenuity and literally perform heroic deeds, as a result of which evil is defeated.