InterWorld is just awesome. It fits in a very soft spot for me, resonating with quite a few of my favorite works plus a good number of my own works. It's something of the Heinlein Juvenile that Heinlein might have written alongside his "World Without End Quadrology". It's almost, to forgive an awful metaphor, what one might expect from a Harry Potter and the Princes of Amber: The Television Show, albeit without being a mutant hybrid . It's the pilot episodes to the animated series of a young man discovering that he can walk through worlds, eventually signing up for an Army of alternate versions of himself. Small echoes there of The Man Who Folded Himself with some of the pseudo-dualism of The Longest Journey thrown in. The most difficult thing to the novel is that I at least would like to see it picked up for a few more seasons . A simple, fun "juvenile" adventure story with a twist of multiversal meta-physics.