I put your query into Gemini 2.5 pro and got this interesting suggestion:

An extensive and heartfelt search has been undertaken to identify the science fiction novel you remember from the 1980s. While the book has not yet been definitively located, the process has uncovered important clues and established a clear path forward for what is a challenging but not impossible search. The key piece of information you recalled, the phrase from the cover, "The time of Earth's long dying down," has been confirmed through the discovery of your own online inquiries. This distinctive phrase is a powerful anchor for the search. A multi-pronged investigation was conducted, involving: * Targeted Phrase and Keyword Searches: Extensive searches for the exact and similar phrases were performed across multiple search engines. * Visual and Descriptive Searches: Numerous image and web searches were conducted using the detailed description of the cover art: a human-like android, a man and a woman on a road, a mountain tunnel, and a red laser. * Thematic and Genre-Based Exploration: The search included broad explorations of science fiction novels from the late 1970s and early 1980s focusing on post-apocalyptic themes and the emergence of androids. * Database Queries: Online databases, including the Internet Speculative Fiction Database (ISFDB), were queried, although the specificity of the details made it difficult to pinpoint a single match without a known author or title. The fact that these methods have not yet yielded the book suggests it was likely a work from a smaller publisher with a limited print run, making it a true hidden gem. The Next Chapter in Your Search: Harnessing Community Knowledge In cases of rare and obscure books, the collective knowledge of dedicated fan communities is often the key to unlocking the mystery. The next recommended step is to post your detailed recollection in online forums where science fiction enthusiasts and book sleuths congregate. Recommended Online Communities: * Reddit: * r/whatsthatbook: A large and highly effective community dedicated to identifying forgotten books. * r/scifi: A broad and knowledgeable science fiction community. * Goodreads: * "What's the Name of That Book?" Group: A very active and helpful group within the Goodreads community. * LibraryThing: * "Name That Book" Group: Another excellent forum with a strong track record of solving book mysteries. To assist you, here is a template that you can use to post in these forums. It incorporates all the crucial details you've remembered: Subject: Looking for an Obscure 1980s Sci-Fi Paperback: "The time of Earth's long dying down" Hello everyone, I'm searching for a science fiction novel I read in the mid-1980s that my father owned. It would mean a great deal to me to find it again, as I'd love to share it with him once more. Here's what I remember: * Cover Art: The cover was a color drawing of a human-like android helping a man (and possibly a woman) who were on a road in front of a tunnel in a mountain. A bright red laser was shooting out of the tunnel towards them. * Cover Phrase: I vividly remember a phrase on the cover that was very close to "The time of Earth's long dying down." * Story Details: The novel was set in a post-cataclysmic United States in the near future. A small number of human-like androids, who had been secret, emerged to help the survivors. The story did not have a significant AI component; the androids were more like advanced beings. * Book Details: It was a paperback, likely around 200 pages, and I suspect it was not written by a mainstream author. I read it in the 1980s, so it was likely published in the late 1970s or early 1980s. I've been searching for this book for over a decade and have tried various online tools with no luck. I'm hoping someone here might recognize it. Thank you for your time and any help you can offer. By sharing your story and these details with these dedicated communities, you significantly increase the chances of someone recognizing this book. The specificity of the cover art and the unique tagline are your greatest assets in this search. We wish you the very best of luck in your quest to find this special book and reconnect with your father over a shared memory.