A collection of science fiction stories and essays by two authors written in the 50-70s of the last century. The works of the collection were scattered on the pages of periodicals (magazines "Knowledge is Power", "Technology for Youth", "Literary Newspaper") and had never been published under one cover before. Contents: Sergei Zhitomirsky. Green Bridge (story) Sergei Zhitomirsky. One chance in a thousand... (story) Sergei Zhitomirsky. “Project-40” (story) Sergey Zhitomirsky. Error (story) Sergei Zhitomirsky. The Devil's Wall (story) Sergei Zhitomirsky. Return to the same world (story) Sergei Zhitomirsky. “The Third Commodity” (essay) Sergei Zhitomirsky. On the threshold of space (essay) Sergei Zhitomirsky. New transport of the city - “flower” (essay) Ivan Efremov, Alexander Studitsky, Lev Zhigarev.  About the literature of winged dreams (article), Lev Zhigarev. Guinea pig (story) Lev Zhigarev. Green light (story) Lev Zhigarev. In 1960... (essay) Lev Zhigarev. Who's there? (story)