The premise is Josette Dupre, Captain of the airship Mistral, is the toast of Garnia after having scored a number of victories against the Vinzhalia army. Docked for repairs, she finds herself courted by the brother of perpetual irritant Bernat. Her hometown of Durum remains under the control of Vinzhalia, however, and she is determined to retake it at any cost.
By Fire Above is a very different book from The Guns Above with a much greater focus on characterization as well as personal relationships. There's still plenty of airship-on-airship action but we get more insight into what makes Josette tick as well as her softer side which Bernat never gets to see (mostly because he's an enormous jerk even with all of his character development).
I actually liked Bernat's brother and Josette's romance with him. While Bernat definitely wants something with Josette, I prefer the two as friends due to the fact it's rare to see a male and female lead not develop a romance in these kind of books. Also, it would be way too weird to have them get together given Bernat finally admits to sleeping with Josette's mother (not that there was any doubt to that effect).
The conflict betwene Garnia and Vinzhalia also remains one of my favorite fictional wars due to the fact Robyn Bennis makes no bones about the fact they're morally equivalent. Both sides are throwing thousands of their citizens into the front lines over land which neither actually cares about that much. At one point, Josette is forced to confront the fact had she been born in Vinzhalia, she'd feel every bit her overwhelming patriotism for them instead of Garnia.
Honestly, I like the cynicism of the Signal Airship series toward war while simultaneously having protagonists who are of the mind it's their only means of financial as well as social advancement. They are full of loyalty for a nation which doesn't deserve it and ire for a nation which doesn't warrant it but that's just how real life is. You have your team and their team with the regular people caught in the middle.
My favorite part of the book is definitely Josette's mother who provides a fascinating perspective from the "people on the ground." Despite the fact she has many deplorable traits, I was kind on her side with the idea Garnia is an awful place so why bother serving it (same as Vinzhalia). The fact she's such a contrast to the "heroic" Durum resistance that is just making things worse for themselves is refreshing. I did find the "twist" of her and Josette's relationship a bit unbelievable but it was still a fun revelation.
In conclusion, if you enjoy a gritty but still rousing tale of war in a pseudo-Victorian/WW1 era then this is a great steampunk novel. Josette, Bernat, and the rest of the cast are highly entertaining as well as play off each other magnificently. I will definitely be picking up the third novel in the series and hope it continues indefinitely, even if I'm not particularly invested in our heroes' side winning.