1951 novel by Clifford D. Simak
'One of those complex and enormously inventive stories... based on some real, honest, practical ethical thinking. It is an idea book.'- Groff Conklin in Galaxy Science FictionAsher Sutton has been lost in deepest space for twenty years. Suddenly arrives a warning from the future, that he will return- and that he must be killed. He is destined to write a book whose message may lead to the death of ... goodreads.com