POV: navani
Summary
Light, Navani decides, is far more interesting than she had ever realised. Locked into Raboniel's library room with a guard at the door, she sets about closing the holes in her own education. She orders texts brought from Kholinar and across the tower, and Raboniel — true to the bargain — has them all delivered without question. Each day Navani sends mundane instructions to her scholars, hides ciphered messages in them that decode to nonsense to occupy whichever spren Raboniel has set to read them, and spends the rest of her hours on the topic that has begun to obsess her. What is light? Ancient scholars disagreed: some claimed it had a measurable weight; others, that it was the force of its motion one could measure. She had simply taken it for granted her whole life.
She rebuilds an old experiment from her books — a candle in a box, a focusing hole, a prism — and sees a candle-flame separate into a rainbow on her paper. With more attempts she assembles a second prism that recombines the components into pure white light. She tries the same setup with a diamond infused with Stormlight: the rainbow comes out the same, but the blue band is enlarged. Voidlight produces one with a vast violet band, the others reduced to slivers. Her books had warned that colours of light should only brighten or dim bands, not enlarge them.
She runs the experiment on the sphere of Towerlight. Two separate, distinct rainbows split out, overlapping but unmixed; a second prism gives her only two beams, one white-blue and one white-green. The green one she suspects is Lifelight — close enough to Stormlight that without the comparison she would never have known the difference.
She digs through the trunk Raboniel's people fetched for her and finds her journals. The day of Gavilar's death is still the most painful in her life, and she had recorded her impressions of it six separate times, in six different moods. She had spent the years after building the public legend of Gavilar the unifier — exactly what he had threatened to leave her in retaliation if she withheld it — and she does not like to revisit the man underneath. But she opens the journal and rereads her account of confronting him in his study that night. He had been showing twenty or thirty spheres to strangers who afterward vanished. Some had been distinctly off — violet and black, somehow glowing, somehow seeming as though they should swallow light instead of shed it. She compares the description to the pale green Lifelight she has just split out of Towerlight and wonders for the first time whether some of those gemstones could have held Lifelight too — and whether the air-warping ones could be something else entirely. She forces herself to read further, to Gavilar's worst line — that she was its opposite, a thing that destroys light. The same word, opposite, that Raboniel keeps reaching for.
The guard at her door begins to hum, and Raboniel enters, trailed as usual by the blank-stared Fused with the topknot and skin pattern so like her own. The silent Fused walks to the wall and stares at it; Raboniel comes to the desk and bends close enough that her orange-red hair sweeps the table. The Towerlight experiment delights her — Stormlight and Lifelight, just as she said. Navani uses the moment to deflect with the genuine puzzle: illumination cannot be stored in gemstones, yet Stormlight can, and Stormlight gives off illumination. The captured Light must therefore be different from what it radiates. Raboniel ignores it: can the Lights be mixed?
Navani drops her own question almost casually — has Raboniel ever heard of spheres whose air warps as though they were very hot? Raboniel's rhythm cuts out. There are theories. Matter has opposites; negative axi destroy positive axi when combined; some have wondered whether there might be a negative light too, an anti-light, that would annihilate its positive on contact. She had discarded the idea, assuming Voidlight already filled the role of opposite to Stormlight. Navani goes very cold. She had told her own people, the ones she trusted with Szeth's strange sphere, to experiment with the air-warping Light — and wonders, suddenly, if they have inadvertently mixed it with ordinary Voidlight, and what that has cost them.
Raboniel sweetens the offer: if Navani can mix Stormlight and Voidlight without destroying them, Raboniel will take her troops and walk away from the tower. The knowledge is worth more to her than any position. Navani does not believe her for a heartbeat, but agrees, and probes — why is Raboniel so set on this? — and gets only the long view: the war has stretched too long, and she wants to end it, *for all our sanity.*
In the corner the silent Fused has begun talking louder, asking the wall if anyone has seen her mother. Raboniel hums and glances over, then tells Navani softly that the lost femalen is her own daughter — that one of her younger hypotheses had been that mother and daughter, serving together across the long ages of being reborn, might help one another stay sane. She has long since accepted that hypothesis as disproven. She walks her daughter out of the library; the daughter is still asking after her mother as the door closes, and Navani thinks she sees a wince of grief on Raboniel's face as she goes.