The setting is the Multiverse or all the different possible versions of realities our world could have taken. Two factions at opposite ends of the multiverse continuum are fighting for supremacy, destroying worlds with impunity.
In our world Joey Harker takes a wrong turn, and first winds up in a world very similar to our own, except that his mother has a fake arm, and her offspring is a girl Josephine, who looks very much like him, just a female version. In the next world, it turns out he drowned in the river a couple years ago, instead of having a close brush with death, and getting a huge lecture from his father on water safety. Another look-alike Joe Harker look-alike J is sent to rescue Joey Harker before the warring factions can use his soul for energy in their never-ending war. The Joe Harker look-alikes vary widely from girls with wings, to cyborgs with implants. This was a quick and enjoyable read. It leaves room for a sequel. Lastly, I liked the mudluff sidekick.