While I love infinitely rich universe that we can provide the SF literature, this book shocked me. The story is implausible then that, contrary to popular belief, science fiction is often supported by sound scientific references and / or psychological. There is no acceptable explanation is that some men could emerge from a cave like fresh roses after 50 years. Culture shock is hardly addressed and quickly forgotten. Relations between the two protagonists are boring possible with the very US centric scruples that exasperate me ("it is for life", fidelity, monogamy while we are in a post-apocalyptic story and he surely there other priorities). The narrative construction is packed blunders. In short, if you do not want to waste your time, forget this book. Give me instead a good Catherine Asaro, mix of hard science and fiction, or Robert Heinlein, always tender with his female characters and then I run.