The plot is about the deciphering of some alien messages that reach Earth. The first one is deciphered by a young SETI researcher, who is also responsible for submitting her response. 38 years later, a second message arrives and again, the SETI researcher, this time elderly but having applied a rejuvenation treatment (which has failed and has left her on the verge of a death from old age) deciphers it, while her husband, whose treatment has worked well, explores his new youth.
The book discusses the role of technology in the future development of the human being, moral questions about treatments to extend the longevity of people, abortion, the existence of God and many other moral dilemmas to which Sawyer has us accustomed to raise in your books.
Like the rest of Robert j. Sawyer “Back Back” is 100% recommended and it is worth spending the few hours it takes to read.