Reviewed by: InterWorld April Spisak Gaiman, Neil InterWorld; by Neil Gaiman and Michael Reaves. Eos/Harper Collins, 2007239p Library ed. ISBN 978-0-06-123897-0$17.89 Trade ed. ISBN 978-0-06-123896-3$16.99 R Gr. 5-7 Fourteen-year-old Joey had no idea that his utter inability to navigate was actually a sign that he is destined for greater things. After taking a wrong turn in his city and suddenly slipping into an alternative form of his Earth, Joey learns that all of his navigational talent lies in traveling between dimensions. Unfortunately, it is a dangerous time to be a Walker, one who is aware of and can travel between dimensions, as the Hex and Binary, two evil groups that seek to conquer all worlds, are each growing in power and setting their sights on using the Walkers for their own nefarious purposes. After being rescued from the bad guys, Joey joins a resistance force; even as he struggles to survive a mentally and physically grueling boot camp, however, Joey is distracted by the fact that every member of the small army with whom he is training is an alternative version of himself, drawn together from parallel worlds. Joey is far from the perfect hero: even though his Walking skills may be unequaled, his decision-making abilities are flawed, he can't seem to keep out of life-threatening situations, and for a while his only friend is a sentient bubble. Joey's weaknesses are effective, as readers will sympathize with his errors and imagine their own responses to being faced with numerous more perfect and better-evolved versions of themselves. The lightning pace, flashy descriptions, and the movie-ready twist of having all of the characters essentially being the same person will all be appealing to television and film fans, evoking the timing and strong images of a visual production. And as in any good sci-fi movie, the open-ended conclusion will leave readers demanding a sequel to see what happens to Joey (and all of his other incarnations) next.