She had found Voidlight’s opposite tone. But how could she create Light that expressed this tone? For answers, she looked to nature. A magnet could be made to change its polarity with some captive lightning, and another magnet could realign the pole. But Raboniel had mentioned they could magnetize an ordinary piece of metal that way too.

So were they really changing the polarity of the magnet? Or were they blanking the existing polarity—then rewriting it with something new? The idea intrigued her, and she made a few key requests of her jailers—some objects that would have to be fetched from one of the labs near the top of the tower.

Soon after, Raboniel came to check on her. Navani braced herself. She’d been planning for this.

“Navani?” the Fused asked. “This latest request is quite odd. I don’t know what to make of it.”

“It’s just some esoteric lab equipment,” Navani said from the desk. “Nothing of any real note, though it would be fun to use in some experiments. No bother if you can’t find it.”

“I authorized the request,” Raboniel said. “If it is there, you shall have it.”

That was a rhythm to express curiosity. She made a note in her book; she was trying to list them all.

“What are you working on?” Raboniel asked. “The guard tells me of a terrible sound you have been making, something discordant.”

Damnation. The new tone didn’t sound the same to a Regal. Could she explain it away? “I’m testing how atonal sounds influence Voidlight, if at all.”

Raboniel lingered, looking over Navani’s shoulder. Then she glanced at the floor, where a bucket of icy water, with snow from outside, held a submerged gemstone. It was an attempt to see if temperature could blank the tone of Voidlight.

“What are you not telling me?” Raboniel said to a musing rhythm. “I find your behavior … intriguing.” She glanced to the side as her daughter trailed into the room.

The younger Fused was drooling today. Raboniel had a servant periodically put a cloth against the side of her daughter’s mouth. It wasn’t that her face was paralyzed; more that she didn’t seem to notice or care that she was drooling.

“You write about something called ‘axi’ in our notebook,” Navani said, trying to distract Raboniel. “What are these?”

“An axon is the smallest division of matter,” Raboniel said. “Odium can see them. Theoretically, with a microscope powerful enough, we could see little balls of matter making up everything.”

Navani had read many theories about such a smallest division of matter. It spoke to her state of mind that she barely considered it a curiosity to have such theories confirmed by a divine source.

“Do these axi have a polarity?” Navani asked, as she monitored the temperature of her experiment.

“They must,” Raboniel said. “We theorize that axial interconnection is what holds things together. Certain Surges influence this. The forces between axi are fundamental to the way the cosmere works.”

Navani grunted, writing another notation from the thermometer.

“What are you doing?” Raboniel asked.

“Seeing if a colder temperature changes the vibrations in a gemstone,” Navani admitted. “Would you hold this one and tell me if the rhythm changes—or grows louder—as it warms up?”

“I can do that,” Raboniel said, settling down on the floor beside the desk. Behind, her daughter mimicked her. The attendant—a singer in workform—knelt to dab at the daughter’s lips.

Navani took the gemstone out with a pair of tongs and gave it to Raboniel. Though Navani could faintly hear the tones of gemstones if she pressed a lot of them to her skin, her skill wasn’t fine-tuned enough to detect small changes in volume. She needed a singer to finish this experiment. But how to keep Raboniel from figuring out what she’d discovered?

Raboniel took the sphere and waited, her eyes closed. Finally she shook her head. “I can sense no change in the tone. Why does it matter?”

“I’m trying to determine if anything alters the tone,” Navani said. “Creating Warlight requires a slight alteration of Odium’s and Honor’s tones, in order to put them into harmony. If I can find other things that alter Voidlight’s tone, I might be able to create other hybrids.”

It was a plausible enough explanation. It should explain her requests for plates and other devices, even the ice.

“A novel line of reasoning,” Raboniel said to her curiosity rhythm.

“I had not thought you would take notice,” Navani said. “I assumed you were busy with your … work.” Unmaking the Sibling.

“I still need to bring down the final node,” Raboniel said. “Last time I touched the Sibling, I thought I could sense it. Somewhere nearby … but it is very, very small. Smaller than the others…” She rose from the floor. “Let me know if you require further equipment.”

“Thank you,” Navani said from her desk. Raboniel lingered as Navani recorded her notes about the ice water experiment.

Navani managed to appear unconcerned right until she heard the plates being shifted. She turned to see Raboniel pulling out the new one, the one she’d hidden beneath several others. Damnation. How had she picked out that one? Perhaps it showed the most use.

Raboniel looked to Navani, who forced herself to turn away as if it were nothing. Then Raboniel played it.

Navani breathed out quietly, closing her eyes. She’d racked her mind for ways to hide what she was doing, taking every precaution she could … but she should have known. She was at such a severe disadvantage, watched at all times, with Raboniel always nearby. Navani opened her eyes and found Raboniel staring wide-eyed at the plate. She placed a sphere of Voidlight and played again, watching the Light eject from the sphere.

Raboniel spoke to a reverential rhythm. “A tone that forces out Voidlight?”

Navani kept her face impassive. Well, that answered one question. She’d wondered if the person playing the note needed the proper Intent to eject the Voidlight, but it seemed that creating the plate to align to her hummed tones was enough.

“Navani,” Raboniel said, lowering the bow, “this is remarkable. And dangerous. I felt the Voidlight in my gemheart respond. It wasn’t ejected, but my very soul cringed at the sound. I’m shocked. And … and befuddled. How did you create this?”

“Math,” Navani admitted. “And inspiration.”

“This could lead to…” Raboniel hummed to herself, then glanced at the bucket of ice water. “You’re trying to find a way to dampen the vibrations of the Voidlight so you can rewrite it with a different tone. A different polarity. That’s why you asked about axi.” She hummed to an excited rhythm. And Damnation if a part of Navani wasn’t caught up in that sound. In the thrill of discovery. Of being so close.

Careful, Navani, she reminded herself. She had to do her best to keep this knowledge from the enemy. There was a way, a plan she’d been making should Raboniel intrude as she had. A possible path to maintaining the secrets of anti-Voidlight.

For now, she needed to seem amenable. “Yes,” Navani said. “I think what you wanted all along is possible, Raboniel. I have reason to believe there is an opposite Light to Voidlight.”