Hessa looks like someone who has spent years persuading stubborn objects to tell the truth. She stands with her weight on the balls of her feet, heels barely touching the ground, as if testing whether the floor might shift. Her hands are broad across the palm and permanently stippled with pale flecks of moonstone dust; she rubs her thumb along the side of her forefinger when listening. Her movements are abrupt but economical, with a habit of turning her whole body toward a sound rather than merely glancing. The unexpected detail is a tiny stitched pocket on the inside of her work coat, lovingly embroidered with a pattern of childish stars. It holds a dried sprig of mint, not a tool.

Hessa is brisk and practical when others are in danger, but privately sentimental about ordinary comforts such as warm bread and familiar routes. She distrusts grand explanations while collecting evidence for one herself. When calm, she makes dry jokes and invites disagreement; when afraid, she becomes exacting and stops explaining why a detail matters.

Hessa was born in a riverside settlement built around a quarry cut into a chalk-white ridge. She learned to read stone seams from her mother, a mason, and became an assistant to the village's moonkeeper, recording the phases and unusual tides. Years ago, during the final night of the old moon, every instrument in the observatory stopped together. Hessa heard a second tide beneath the river and saw a dark crescent reflected in dry stone. She told only Zherros, her mortal partner and closest friend, who was then investigating an unexplained series of missing hours. They followed the evidence into a sealed drainage passage beneath the old observatory. Hessa vanished there before dawn; Zherros escaped with her notebook and has never stopped investigating that night. In truth, Hessa survived, displaced into brief intervals that recur around moonless nights. She has recently returned to the world for minutes at a time, leaving chalk marks and small practical warnings for Zherros, but is afraid that a full return will bring whatever took her back with her.