The Wasp Empire has been quiet for the past couple of years, so our protagonists (the ones who survived the previous book) (for bleeding and haunted values of "survived") head off to the semi-lost Beetle city of Khanaphes. The place is stone-age (an unsubtle riff on Ancient Egypt), which confuses everybody: it's not that darn lost, and the Beetle-Kinden who live there are not among the Inapt races of the world. Why do they insist on living in the past? And will they change their mind about crossbows and mortars when an army shows up? (You didn't buy "quiet" did you? Ha ha.)
Big battles, big character reunions, interesting story progression on many axes; tighter focus (one city, albeit with many threads); and a deeper look at the Apt/Inapt divide and what it really means for Bug World. I like it. I understand that book six is already out, and I will go get it without hesitation.