Beginning well before Plato s allegory of the cave and continuing to modern scientific breakthroughs from relativity to quantum mechanics, as well as to pop cultural icons like Twilight Zone and Star Trek, human beings have imagined, even longed for, alternate realities. Lawrence M. Krauss, one of the most gifted and engaging of writer-scientists today, examines why we have often believed that the answers to the great questions about existence lie in the possibility that we live in a universe more complex than we can see or otherwise sense. Drawing on work by scientists, mathematicians, artists, and writers from Einstein to Picasso to C. S. Lewis Hiding in the Mirror explores whether extra dimensions simply represent abstract speculation or hold the key to a deeper understanding of the universe.