Vladimir Konsinov, nicknamed Vok, an athlete-fencer, is faced with the question of how to live further. Suddenly, he is contacted by an alien octopus that looks like a huge stuffed toy. He invites Vok to go to another planet, to the Middle Ages, where he becomes an observer, a spy, and helps the octopuses figure out whether it is worth making contact with the civilization there. Vok agrees - and plunges into the life of an alien planet, where he calls himself Count de la Costa, tries to apply his professional skills, as well as scraps of knowledge that every modern person carries with him.