on Earth 3, so steam is a primary power source among the natives. Earth 4 (Antik) - a world that, in many respects, evokes a Greco-Roman utopia. For example, slaves are allowed to rebel twice a year. If they succeed, they can become free citizens and have their own slaves. Earth 5 - a world where human beings mate in cycles, coming into heat during the spring. It's more advanced than Earth 3 but less advanced than Earth 2. Earth 6 (Tverd) - a world dominated by repressive theocracies. The dominant church practices a "warped, lethargic" version of Christianity. This world is known for comparatively advanced bio-technology and ignorance of electricity. Earth 14 (Janus) - a world with bitterly cold winters and hot summers. Spring is the only season when the weather is anywhere close to tolerable. This version of Earth has no moon and no magnetic field. Although most functionals assume Earth 14 is uninhabited, a functional Kirill encountered in Final Draft'' insisted that there was some animal and human life that survived by migrating along with the spring weather. Earth 16 - a world where Earth changed little over the course of billions of years. It's volcanically active, radioactive, oxygen-poor and generally inhospitable to living organisms, but it is stated in Final Draft that animal-like voices are sometimes heard from there. Earth 17 (Preserve) - a world completely devoid of human life. It's a popular resort among the Functionals and their allies. Earth 22 (Nirvana) - a universe with no native animal life. The planet's surface is covered with plants that produce a narcotic substance that puts any human being within proximity into a drugged stupor. Functionals use this universe as a political prison for their enemies. The children born in this universe are more resistant to the effects of the plants than their parents, but they aren't completely immune. Sources Чистовик-3 Notes Post-apocalyptic novels 2000s adventure novels Russian science fiction novels Novels by Sergey Lukyanenko Novels about parallel universes 2005 novels 21st-century Russian novels