This series just keeps getting better. With every installment, we see more of the kids' lives and their universe, and it keeps getting richer and more interesting. The girls themselves continue to be great, and I love, love, love their parents. The adults in this volume really shine, but not in a way that will loose kids, I don't think (it didn't loose my nephew, anyway. He's a big fan of this series, too, at age 10).
The stakes were higher and the tone maybe a little darker in this book. There's the looming chance of war breaking out again, over something fundamentally stupid (not the girls' fault! At all! Seriously, they're just there to witness it), and everyone on "our" side is working feverishly to ward it off. The reader can't help but notice the traces of the last war - how Tallulah's dad, Hank, has a missing leg and Sanity's mom is missing an eye, for example - and that brings home the reality of what they're trying to prevent. The scenes of everyone in the various space settlements battening down the hatches preparing for the worst - including Tallulah's mom and brother (both home sick with the flu) - does the same. For all of that, though, the fundamental elements of what makes this series great - the humor, the relationships, the madcap genius and bravery of the titular characters - is still there in spades. It's just a really good book.
I also love Tallulah's quote about bad ideas being sneaky, because they seem like good ideas while you're having them. That whole conversation with her dad is amazing. I hope I can parent like that some day.
A++ I love it.