The Fold is an interesting sci-fi novel based on the theory of folding space in order to travel long distances quickly, hence the title. Unlike many other sci-fi books where folding space is used for space travel, this book takes place solely on earth and centers on a secret DARPA project where scientists have built the Albuquerque Door - a matched set of rings that allows anyone, or anything, to travel instantly between them. Clearly this is going to be mankind's greatest invention and it will change civilization forever; however, something about the door just doesn't add up.
Despite hundreds of successful tests, the project sponsor has a gut feeling that something isn't quite right and he wants to get to the bottom of it before the next round of funding is provided. He convinces his friend Mike to investigate the project because Mike is one of the smartest people on the planet and has an eidetic memory which allows him to remember everything he ever sees. The scientists that work on the project are hiding behind a tight non-disclosure agreement and will share no information with their sponsor about "how" the door works, so the truth will need to be puzzled out Sherlock Holmes style.
The first two-thirds of the book are all about peeling back the onion and unraveling what exactly is going on with the door. Despite the fact that quantum mechanics and multi-verse theories are tossed about, it is easy for a reader to align with Mike because he is not a trained scientist and he breaks down the techno-babble into easier concepts. The Fold also manages to stay fun with quirky humor, a number of nerdy pop culture references, and even quantum donuts.
The story does eventually take a sideways turn which might not be appreciated by everyone. It is hard to say much about where it goes without spoiling it, but suffice it to say that it does get a little weird towards the end. If that concerns you then you can get a bit of a spoiler by checking out the book "14" by Peter Clines which is a bit of a sister story to this. If the concept of "14" does not seem interesting to you then perhaps you should steer clear of this book as well. I personally did not know anything about "14" and I still enjoyed this book anyway.
For audiobook fans, Ray Porter does his usual excellent job on the narration. He handles the many different character voices well, including the female characters.