From the author's introduction:

A popular topic in science fiction these days is the multiverse, the concept of an infinite number of parallel worlds. Remember, though, that the multiverse is not as far away as you suppose. Each book that you read takes you into a new universe. When you enter a bookstore or a library you are in the midst of thousands of portals to other worlds. To enter all you have to do is follow the words that the authors have set down to guide you. If they have done their jobs effectively, you find yourself in strange lands and alternate timelines with all sorts of different types of characters. The best part is that you can do it anywhere and anytime. Just open up the door, namely the cover of the book, and dive in. I compile these collections of book reviews to serve as maps leading to wondrous worlds. I wish you joy, amazement, prosperity, fun, and adventure in your explorations.