In just a few centuries, “ZASLON”, who discovered the possibilities of genetic engineering, radically transformed the world: concrete jungles, landfills and diseases were replaced by cities with living houses, garbage-eating genetically modified organisms and people of the new evolutionary stage homo cynthia, immune to viruses. However, not all of humanity cordially accepted the artificially accelerated progress to unimaginable proportions: the last representatives of homo sapiens fenced themselves off from the biosynthetic world in the closed city of Spadburg, where they began to conduct their own experiments to cleanse humanity from the interference of scientific thought. April 24, 3089 is a great and joyful day when Protestants managed to revive the disease that had once been defeated by the Zaslonovites. Now it’s up to a nine-year-old boy named Tosha to roll back evolution—the first human of the species homo sapiens in five centuries... and a carrier of a cancerous tumor.