Okay, I'm off the trilogy soapbox now and back to the book itself. This is a wonderful sequel to an original steampunk concept with a crazy inventor type coming up with crazy ideas that can be utilized for good and evil. There's a plucky heroine - Katherine - and a somewhat mysterious romantic lead, Lane. Plus sidekicks, villains and some characters who may be playing both sides. The first book is set in England and the second in France and the setting details (including architecture, clothing and weird inventions) are rich and wonderful. The tone is delightfully reserved, despite the pluckiness of the heroine and her determination to save the world and protect the people she loves, including actually LOCATING one of the people she loves in this second book.
While I tend to gravitate toward fast-paced action-adventure stories, the tone of this series is more muted, but I still enjoyed both books and read them very quickly. The characters are engaging and the plots are unique, even among the existing steampunk genre. I found the second book a little slower than the first to pick up steam (no pun intended ... well, maybe just a little) and get the plot moving, but once the gear shift was engaged, I was hooked. Highly recommend this (fingers crossed) DUOLOGY. Very suitable for older and younger readers alike.