After a nuclear war, humanity was thrown back into the dark ages. Not wanting to return to its former dangers, it builds its own world in the vastness of the dead world. Faced with many difficulties on their way (wishing to regain their former power and technology, hordes of mutants), people enter the golden age. But all this collapses when our world merges with another. Foreigners (races inhabiting another world) come to it. Once again, calamity envelops the human race. Chains of slavery bind them. The book takes place in medieval times.