Cethra looks as if she has spent decades listening to bad weather through stone. Fine wind-roughened lines cross her brow, and a faint dusting of pale glass grit catches in the creases beside her nose. She moves with economical, measured steps, stopping abruptly as if she has heard a distant clock no one else can hear. Her most unexpected detail is a bright saffron scarf knitted in a child's uneven stitches, carefully mended at the fringe and worn even with formal robes.

Cethra is curious enough to ask a stranger for their worst theory, yet cautious enough to verify every detail before acting on it. She is warm with frightened people and unsentimental with those who use fear to control others. In private she can be funny and almost playful; when a decision has lives attached to it, she turns exacting and hard to interrupt.

Cethra was raised in Kettlecut, a riverside town built around glasscutting furnaces. Her mother, Sella, cut lenses for surveyors; her human father, Hadrik, kept the furnace drafts steady. As a child, Cethra learned that a warped lens could make a straight road appear to bend, a small lesson that became the foundation of her obsession with what people mistake for certainty. She studied under the diviner Tarek, whose predictions were accurate but never merciful. During the siege of Kettlecut, Tarek foresaw that the town's eastern gate would fall. Cethra trusted his vision and helped evacuate the western quarter, but the gate held and the riverwall collapsed instead, drowning dozens of neighbors. The failure did not make her reject foresight; it taught her that a prediction is a possibility, not permission to stop choosing. She left the town, became an adviser to competing courts, and eventually returned to build an observatory above the shuttered furnaces. Now her former apprentice Gavit is selling fragments of her old predictive charts to a border prince, while Sella's health is failing and the town council wants Cethra to decide which threatened district to save first.