The concept of stepping to adjacent universes is one of those
plot devices that, while opening up a huge scope for
fiction, also, like the Star Trek transporter, threatens
to torpedo drama. If you can escape peril simply by stepping
away to another universe, how can characters be placed
in difficult circumstances? In Star Trek, there always has to
be some reason (“danged pesky polaron particles!”)
why the transporter can't be used to beam the away team out
of danger. Here, the authors appear to simply ignore the
problem. In chapter 30, Joshua is attacked by elves riding
giant hogs and barely escapes with his life. But, being a
natural stepper, he could simply step away and wait for
Lobsang to find him in an adjacent Earth. But he doesn't,
and there is no explanation of why he didn't.