And Iari will need his friendship, as well as his protection, when her virtue and sense of justice lead her to pursue the murderer at all costs. So when a wichu arithmancer is found brutally murdered, Gaer is in a unique position to help Iari investigate. Gaer is an expert in arithmancy, the SF magic system introduced in Eason’s previous books. She’s been assigned to escort Gaer, an ambassador (and spy) from the faction of vakari that defected from the Protectorate, as he researches the effects of the Weep on the planet Tanis. Iari is a tenju “templar,” meaning a member of a sort of religious military force called the Aedis. This rip, the Weep, supplied surges of horrifying monsters, the Brood, and hasty alliances were made by all factions in order to deal with the new threat. Vakari who were opposed to the Protectorate eventually broke away, starting a civil war, and that war came to an end when the Protectorate accidentally ripped a hole in reality itself.

Years have passed since the events of How the Multiverse Got Its Revenge (2021), and the war between the colonizing forces of the vakari Protectorate and, well, everyone else is long over. An unlikely duo searches for the culprit behind a gruesome murder in Eason’s new series set in her Arithmancy and Anarchy universe.

It seems there is still dangerous arithmancy in Windscar-but the source isn't who Iari expected, and they're far worse than the separatists. As they delve into the ruins, they find remnants of long-ago battles, bits of broken armor and mechas-which unexpectedly reanimate and attack. Included in Iari's team are Char, a decommissioned battle-mecha and newly-joined templar, and Gaer, ostensible ambassador and talented arithmancer. She's worried about surviving separatists and a fresh attempt to upend the Confederation.

Promoted and sent north to the tundra of Windscar, Iari leads a team of templars to investigate ancient, subterranean ruins, which local legend claims are haunted, and which have mysterious connections to the dangerous arithmancy used by the wichu separatists. But after she helped stop separatists from sabotaging the entire Confederation, she discovered a new sort of monster: the rogue-arithmancer, political kind.

As a templar in the Aedis, a multi-species religious organization committed to protecting the Confederation, eliminating extra-dimensional horrors is her job.

Nightwatch over windscar by k eason