Entremonde

InterWorld is a fantasy and science fiction novel by Neil Gaiman and Michael Reaves. The book was published in 2007 by EOS, an imprint of HarperCollins Publishers. It follows the story of Joey Harker who, together with a group of other Joeys from different Earths in other parallel universes, try to stop the two forces of magic and science from taking over all of the Earths in different universes.