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.
The Fold by Peter Clines - quantum donuts for breakfast
