Sequel to the Long Earth, this one started slow but once it had its threads in place moved along. It's less a novel than it is a short story collection of two authors who interwove their tales into a single book. That's not a bad thing, but it does make it feel like a patchwork rather than an narrative. Still, it went in some interesting directions and ended with enough of a bang that I'll look at the Long Mars, the third in the series.