"Tessellations of Indigo & Ivory Snow" follows Dr. Corinne Baptiste, a forensic folklorist who discovers a mysterious violet-inked letter from 1873 that threatens to unravel both space and time in 1913 Montr al. The letter leads her to investigate the disappearance of abolitionists who created a Pan-Diasporic Star Map - a mystical document capable of allowing displaced Black souls to reclaim their erased histories.
As snowbound murders matching constellation patterns begin appearing across the city, Corinne allies with Hiram Knox, a synesthetic cryptanalyst who can hear colors, and Sable-Tine, a shape-shifting shadow being composed of ancestral memories. Together, they must navigate Montr al's labyrinthine underground catacombs while pursuing leads through the salon of Baroness von Adlersberg, whose perfectly symmetrical beauty masks sinister motives.
The investigation reveals a deeper conspiracy: Major Mallory's obsession with restructuring city architecture to harvest temporal energy, threatening to permanently damage the fabric of spacetime. Corinne faces an impossible choice - free Sable-Tine and lose her only connection to solving the murders, or maintain the shadow being's bondage against her moral principles.