Dense, intense, tense, present tense milsf space opera. A weird quasi-religious empire built on some sort of powerful calendar system that exerts mathematical powers which affects weapons and technology ruthlessly crushes heretics with variant calenders - look I dunno, it has its own logic on the page, awesome logic, I should add, because it's fairly mindbending. The Kel are a fanatically military caste with preprogrammed formations that allow them to withstand attacks and launch assaults of their own. Captain Kel Cheris has a knack for mathematics and a talent for adapting Kel formations to heretical standards when calendrical rot reduces the effectiveness of hexarchate approved tactics. That sentence actually makes sense when you read the book.

Cheris is sent to retake a crucial fortress that has fallen to heresy, and her chosen weapon is a revived general who never lost a battle but who went mad and completely wiped out two armies, one of them his own. With the general resident in her own mind and herself elevated to the unwelcome rank of general, Cheris must take the fortress back and watch out for the other general in her head.

Reminiscent of Hannu Rajaniemi, this isn't quite as full on and disorienting - you do find your feet relatively quickly. There's lots of action and intrigue and high-level politics and low-level skullduggery packed into this volume.