An exciting book of show-don't-tell. Military states united under a common N-archy work separate but together to protect the status quo in the following: agreed upon mathematical systems which manifest themselves in physical space as regions that allow or disallow the use of exotic weapons and technologies. Heretics focused on getting a large enough society to use a different base number, calendar, time systems, or even holidays can disrupt the expected area to disable shields, drives, weapons and countless other technologies while enabling others.

People will say it's not sci-fi. It's as much sci-fi as many others accepted in the genre, but know it's not science but space and "math magic" that give it this place. If you like Hannu Rajaniemi's stories you'll probably be happy here as well.

People will also say this book must be read and not listened to. This was not the case for me. I read about 60% of the book and listened to the other 40% on Audible (interspersed, as driving and home time allowed). I had no trouble following and enjoying the book either way.

I went straight to the sequel after finishing.