Humanity has combined biology and cybernetics at the genetic level. People stopped getting sick, aging and dying naturally. The altered physiology did not require sleep and organic food; the biocybernetic person only needed energy. Exmans became the only currency - virtual units of experience, which are the basis of all biocybernetic organisms. When a priceless metal was discovered on Mars - a source of endless energy, earthlings wanted to take possession of it. The war with Mars turned into a disaster for humanity and the entire Earth. From a single human empire, only separate small settlements remained; almost all earthly technologies were destroyed. The landscape and climate of the planet changed, it was covered with a multi-meter layer of radioactive ash. Radiation mixed the human biocybernetic genome with the genes of other living organisms on the planet. Humanity turned out to be vulnerable to nature and evolution.