Unseemly Science - Rod Duncan
So in The Bullet Catcher’s Daughter, Duncan created this nice little world and set up what could've been a pretty long running series of adventures for Elizabeth Barnabus and her alter-ego/brother Edwin. Naturally, in the sequel, he pretty much destroys all of that. Sure, it would be possible to get back to something akin to the status quo, but it'd be tricky, and he's clearly not going for that.
As clever and skillful as Elizabeth demonstrated herself to be, there's always someone better.  And when a few of those people are working together? It's not going to go easy for you.  She's got quite the powers arrayed against her -- she's about to be deported back to the Kingdom, along with dozens of other refugees. When she's safely back on the other side of the border, there are sure to be representatives of the Duke that's been hunting for her waiting. 
Elizabeth's mentee, Julia, continues her education -- emboldened and possibly more headstrong thanks to her recent adventures, yet still naive and idealistic. it's her support for a charity that drives Elizabeth in this novel (well, other than the above). John Tinker, naturally, shows up and is just as simultaneously inconvenient and perfectly helpful as he was before. I'd like to learn a little more about the America he comes from.  
On the run for her life, chased by the government, bounty hunters, and investigating an odd crime (ice shortages -- no, really) -- things start to get strange.  Strange followed by disturbing.  This culminated in an action sequence I (literally) could not turn pages fast enough through. Which was followed by a denouement that in retrospect I think I should've expected, but took me by surprise.
I'm not ready to leave this world, and am so glad to see that The Fall of the Gas-Lit Empire duology has been upgraded to a trilogy, although I haven't the foggiest idea how Duncan is going to achieve any kind of closure in one more book. But I'm looking forward to finding out how he pulls it off.
Source: http://irresponsiblereader.wordpress.com/2015/12/04/unseemly-science-by-rod-duncan