Okay, I really need to recommend this to my younger son – he's the REAL sci-fi/fantasy lover; I'm just a casual sci-fi/fantasy lover. Audible didn't even mention sci-fi/fantasy as it's genre, it listed only "mystery/thriller". It was definitely a thriller, but it wasn't a mystery in the standard meaning, although a lot of what happened was very mysterious :-), it was definitely not a murder mystery.
It had aspects of a fantasy world, some electronics – primarily sci-fi, and there was even a little bit of sci-fi astronomy. I think anyone who enjoys fantasy and/or sci-fi will really enjoy this book.