"So, what do you think it's about?" she asked, as she took a preliminary sip from her cocktail. "Entropy, to start with," he replied. "If only he'd known the Holographic Principle. It follows from thermodynamic calculations that the information content of a black hole is proportional to the square of its radius, not the cube, and the Universe can reasonably be thought of as a black hole. Hence all its information is really on its surface, and the interior is a low-energy illusion. Wouldn't you say that the book is rather like that too?"
The rest of this review is in my book What Pooh Might Have Said to Dante and Other Futile Speculations