Two years after a devastating defeat in the decade-long Spore War, the island nation of Hōppon and its capital city of Neo Kinoko are occupied by invading Coprinian forces. Its fungal citizens are in dire straits, wracked by food shortages, poverty, and an influx of war refugees. Even worse, the corrupt occupiers exploit their power, hounding the native population. As a winter storm looms over the metropolis, NKPD homicide detective Henrietta Hofmann begrudgingly partners up with mushroom-headed patrol officer Koji Nameko to investigate the mysterious murders of fungal and half-breed children. Their investigation drags them deep into the seedy underbelly of a war-torn city, one brimming with colonizers, criminal gangs, racial division, and moral decay. In order to solve the case and unravel the truth, Hofmann must challenge her past and embrace fungal ways. What she and Nameko uncover in the midst of this frigid wasteland will chill them to the core, but will they make it through the storm alive?