InterWorld

An astounding tale of adventure, danger, magic, science, friendship, spaceships, and, oh yeah, the battle to save all the people in all the worlds in all possible dimensions. Joey Harker isn't a hero. In fact, he's the kind of guy who gets lost in his own house. But one day, Joey gets really lost. He walks straight out of his world and into another dimension. Joey's walk between worlds makes him prey to armies of magic and science, both determined to harness Joey's power to travel between the dimensions. The only thing standing in their way is Joey—or, more precisely, an army of Joeys, all from different dimensions and all determined to save the worlds. Now Joey must make a choice: return to the life he knows or join the battle to the end.