If it hadn't been for Stewart's overly politically correct approach to this sequel to "Flatland" by Edwin A Abbott (an obscure victorian satire portraying women as one dimensional lines who are inferior to men), I would have enjoyed this book emensely. Perhaps Stewart felt guilty about Edwin Abbott's commentary on the Victorian prejudices, or maybe he felt it would sell better by saying women are far superior to short-sighted men; either way it was annoying and wholly pointless.
Anyway, it introduces mathematical subjects like fractals and wormholes/time travel in a different and more interesting format to most popular science books. It was funny in parts, and both my mother (useless at maths) and I (taking A-level maths) understood and enjoyed this book. (Saying this, I thought he spent too long explaining some topics, then neglected to explain others thouroughly.)
A great book for those who are interested in widening their maths knowledge, written in a non-patronizing way, especially for a University professor - shame he had to spoil it with the ridiculously PC subplot.