The second book in any series, in my opinion, is the clincher. The first book could be completely awesome, yet sometimes the second book is not so awesome. There are many reasons for this, from the story going in a direction you didn't anticipate to the author simply running out of ideas. Conversely, the second book can be a signal that the series is definitely worth pursuing. Such is the case in the Shadows of the Apt series by Adrian Tchaikovsky. Book two is titled Dragonfly Falling and is even better than the first book in the series, Empire in Black and Gold.
Stenwold Maker has been warning everyone of it for years and now, finally, the Wasp Empire has begun its invasion of the Lowlands. While attacking on two fronts from the east, the Wasps also convince the city of Vek to attack Collegium, Stenwold's home, from the west. As the city of Tark falls and the great army of Sarn is routed one thing becomes clear: unlike many wars in the past, this current war is in the hands of the artificer. As Collegium itself comes under attack, its various scholars all begin to produce their inventions in an attempt to save their city. As devastating new weapons are introduced on both sides, it is clear that war will never be the same again.
This book is a lot more exciting than the first one, but it is also much darker. There are quite a few major battles and the body count is much higher. Of course, this isn't George R.R. Martin, so don't expect Stenwold to suddenly get offed, but there are a surprising number of fatalities. In addition, the concept of death and war are on many of the character's minds as they struggle to deal with loss and the consequences of creating something that has only one purpose: the taking of life. Overall, this darkness does not detract from the story. Rather, it makes it that much more interesting.
Expect more from Adrian Tchaikovsky as his series continues and, I hope, gets better and better. Also, check out Prometheus Books, Tchaikovsky's publishing company, for many more unique and fascinating books.