This made me think of World War I, Pat Barker‘s Regeneration Trilogy (on a much shallower level), Sherlock Holmes (blond), Steampunk (with aether instead of steam engines) and the M M Romance of KJ Charles (without the hanky-panky).
It took me a little to warm up to the main character, it was not love a first sight. The bad guy was a bit one-dimensional. A deeper look at him would have been nice. I hope that some of my favourite side characters from this will show up in the second book. And I really, really wanted to see Grace burn in a fire for a long time.
Good world-building, nice plot, not terribly complex. Overall I liked the story, but wasn‘t glued to the page. I could have done with a trickier mystery and a little more suspense. The bicycle chase was fun. I loved the reveal at the end—I had my suspicions, but guessed wrong and had a wow-moment.
I am pretty sure that I will pick up the sequel at some point.