John Rayburn, his friends, and their doppelgangers from other universes build a transdimenional corporation. However, there old enemies the Alarians aren't finished with them and then there's the matter of John Prime visiting universes on his own, unbeknownst to the rest of the Pinball Wizards...
Sequels. You hate them, right? Yeah, me too. Rarely do they pack the same punch as the original. While Broken Universe doesn't make me forget about my general sequel hate, it does a pretty good job in showing what a sequel could be.
Broken Universe takes what Melko started in The Walls of the Universe and turns the knob up to eleven. Instead of two Johns and two Caseys, we get multiples dupes of John, Casey, Henry, and Grace. They go about building more transfer devices, deal in more than just pinball machines, and generally act like normal people probably would if they had an infinity of parallel universes to explore/exploit.
The Alarians were a decent foe for the first half of the book but I found the Vig to be much more interesting. They were merely hinted at in Walls of the Universe but stepped to the forefront in the second half of the book. I liked that Melko gave them more dimension than just being a transdimensional police force.
The characters of John Rayburn, John Prime, and Grace Home were the most developed. Prime continues to be my favorite character but Grace almost passed him in this one. The contrast between John Rayburn and John Prime drove the book along nicely. Grace really stepped up after what happened to her at the end of the first book.
It's not all peaches and gravy, though. I still don't get why all the Johns and all the Caseys wind up together. I'd much rather see John and Grace as a couple. My only other complaint is that I wanted more. There are still enough unanswered questions for at least one more book.Note:
I did an interview with Paul Melko about the Universe series here.