Midius once told me … told me we could use Investiture … to enhance our minds, our memories, so we wouldn’t forget so much.

Raboniel made good on her promise to leave Navani to her own designs. The Fused studied the shield that protected the Sibling—but without Navani to accidentally act as a spy, Raboniel’s progress wasn’t nearly as rapid as before. Occasionally—when pacing so she could glance out past the guard—Navani would catch Raboniel sitting on the floor beside the blue shield, holding up the sphere full of Warlight and staring at it.

Navani found herself in a curious situation. Forbidden to take part in the administration of the tower, forbidden direct contact with her scholars, she had only her research to occupy her. In a way, she had been given the gift she’d always wished for: a chance to truly see if she could become a scholar.

Something had always prevented her from full dedication. After Gavilar’s death, she’d been too busy guiding Elhokar and then Aesudan. Perhaps Navani could have focused on scholarship when she’d first come to the Shattered Plains—but there had been a Blackthorn to seduce and then a new kingdom to forge. For all she complained about politics and the distractions of administering a kingdom, she certainly did find her way into the middle of both with frightful regularity.

Perhaps Navani should go do menial labor. At least that way she’d be among the people. And wouldn’t risk doing any more damage. Except … Raboniel would certainly never let her go around unsupervised. Plus, the lure of unknown secrets called to Navani. She had information Raboniel did not. Navani had seen a sphere that warped air, filled with what seemed to be some kind of anti-Voidlight. She knew about the explosion.

The thing Raboniel wanted to create was possible. So … why not try to find out how to make it? Why not see what she could actually do? The power to destroy a god. Negative Light. Can I crack the secret?

What if Navani was thinking too small in trying to save the tower? What if there was a way to end the war once and for all? What if Navani really could find a way to destroy Odium?

She needed to try. But how to even start? Well … the best way to encourage discoveries from her scholars was usually to cultivate the proper environment and attitude. Keep them studying, keep them experimenting. Oftentimes the greatest discoveries came not because a woman was looking for them, but because she was so engrossed in some other topic that she started making connections she never would have otherwise.

So, over the next few days, Navani tried to replicate this state in herself. She ordered parts, supplies, fabrial mechanisms—some all the way from Kholinar—and they were delivered without a word of complaint. That included, most importantly, many gemstones bearing corrupted spren to power fabrials.

To warm up, she spent time creating weapons that wouldn’t look like weapons. Traps she could use, if she grew truly desperate, to defend her room or the pillar room. She wasn’t certain how she would deploy them—or if she would need to. For now, it was something scholarly to do, something familiar, and she threw herself wholeheartedly into the work.

She hid painrials inside other fabrials, constructed to appear innocuous. She made alarms to distract, using technology they’d discovered from the gemstones left by the old Radiants in Urithiru. She used conjoined rubies to make spring traps that would release spikes.

She put Voidlight spheres in her fabrial traps, then set them to be armed by a simple trick. A magnet against the side of the cube, in precisely the right place, would move a metal lever and arm the traps. This way they wouldn’t activate until she needed them. She had these boxes stored out in the hallway, as if they were half-completed experiments she intended to return to in a few days. The space was already lined with boxes from the other scholars, so Navani’s additions didn’t feel out of place.

Afterward, she had Raboniel help her make more Warlight for experiments. Navani couldn’t create it by herself, unfortunately. No combination of tuning forks or instruments replicated Raboniel’s presence—but so far as Navani could tell, the Fused also couldn’t create it without a human’s help.

Navani got better at humming the tone, mastering the rhythm. In those moments, she felt as if she could hear the very soul of Roshar speaking to her. She’d never been particularly interested in music, but—like her growing obsession with Light—she found it increasingly fascinating. Waves, sounds, and what they meant for science.

Underlying all the work she did was a singular question: How would one make the opposite of Voidlight? What had been in that sphere of Gavilar’s?

In Vorinism, pure things were said to be symmetrical. And all things had an opposite. It was easy to see why Raboniel had assumed the dark Light of the Void would be the opposite of Stormlight, but darkness wasn’t truly an opposite of light. It was simply the absence of light.

She needed some way to measure Investiture, the power in a gemstone. And she needed some kind of model, a form of energy that she knew had an opposite. What things in nature had a provable, measurable opposite?

“Magnets,” she said, pushing aside her chair and standing up from her notes. She walked up to the guard at her chamber door. “I need more magnets. Stronger ones this time. We kept some in the chemical supplies storehouse on the second floor.”

The guard hummed a tone, and accompanied it with a long-suffering sigh for Navani’s benefit. He glanced around for support, but the only other singer nearby was Raboniel’s daughter, who sat outside the room with her back to the wall, holding a sword across her lap and staring off into the distance while humming. It wasn’t a rhythm, Navani realized, but a tune she recognized—a human one sung sometimes at taverns. How did the Fused know it?

“I suppose I can see it done,” the guard said to Navani. “Though some of our people are growing annoyed by your persistent demands.”

“Take it up with Raboniel,” Navani said, walking to her seat. “Oh, and the Fused use some kind of weapon that draws Stormlight out of Radiants they stab. Get me some of that metal.”

“I’ll need the Lady of Wishes to approve that,” the guard said.

“Then ask her. Go on. I’m not going to run off. Where do you think I’d go?”

The guard—a stormform Regal—grumbled and moved off to do as she asked. Navani had teased out a few things about him during her incarceration. He’d been a parshman slave in the palace at Kholinar. He thought she should recognize him, and … well, perhaps she should. Parshmen had always been so invisible though.

She tried a different experiment while she waited. She had two halves of a conjoined ruby on the desk. That meant a split gemstone—and a split spren, divided right through the center. She was trying to see if she could use the tuning fork method to draw out the halves of the spren and rejoin them in a larger ruby. She thought that might please the Sibling, who still wouldn’t talk to her.

She put a magnifying lens on one half of the gemstone and watched as the spren within reacted to the tuning fork. This was a corrupted flamespren; that shouldn’t change the nature of the experiment, or so she hoped.

It was moving in there, trying to reach the sound. It pressed against the wall of the gemstone, but couldn’t escape. Stormlight can leak through micro-holes in the structure, Navani thought. But the spren is too large.

A short time later, someone stepped up to the doorway; Navani noticed the darkening light of someone moving in front of the lamp. “My magnets?” Navani asked, holding out her hand while still peering at the spren. “Bring them here.”

“Not the magnets,” Raboniel said.

“Lady of Wishes,” Navani said, turning and bowing from her seat. “I apologize for not recognizing you.”

Raboniel hummed a rhythm Navani couldn’t distinguish, then walked over to inspect the experiment.

“I’m trying to rejoin a split spren,” Navani explained. “Past experience shows that breaking a gemstone in half lets the flamespren go—but in that case, the two halves grow into separate flamespren. I’m trying to see if I can merge them back together.”

Raboniel placed something on the desk—a small dagger, ornate, with an intricately carved wooden handle and a large ruby set at the base. Navani picked it up, noting that the center of the blade—running like a vein from tip to hilt—was a different kind of metal than the rest.

“We use these for collecting the souls of Heralds,” Raboniel noted. “Or that was the plan. We’ve taken a single one so far, and … there have been complications with that capture. I had hoped to harvest the two you reportedly had here, but they left with your expeditionary force.”

Navani flipped the weapon over, feeling cold.

“We’ve used this metal for several Returns to drain Stormlight from Radiants,” Raboniel said. “It conducts Investiture, drawing it from a source and pulling it inward. We used it to fill gemstones, but didn’t realize until the fall of Ba-Ado-Mishram that capturing spren in gemstones was possible. It was then that one of us—She Who Dreams—realized it might be possible to trap a Herald’s soul in the same way.”

Navani licked her lips. So it was true. Shalash had told them Jezerezeh’Elin had fallen. They hadn’t realized how. This was better than absolute destruction though. Could he be recovered this way?

“What will you do with their souls?” Navani asked. “Once you have them?”

“Same thing you’ve done with the soul of Nergaoul,” Raboniel said. “Put them somewhere safe, so they can never be released again. Why did you want this metal? The guard told me you’d asked after it.”

“I thought,” Navani said, “this might be a better way to conduct Stormlight and Voidlight—to transfer it out of gemstones.”

“It would work,” Raboniel said. “But it isn’t terribly practical. Raysium is exceptionally difficult to obtain.” She nodded to the dagger she’d given Navani. “That specific weapon, you should know, contains only a small amount of the metal—not enough to harvest a Herald’s soul. It would not, therefore, be of any danger to me—should you consider trying such an act.”

“Understood, Ancient One,” Navani said. “I want it only for my experiments. Thank you.” She touched the tip of the dagger—with the white-gold metal—to one half of the divided ruby. Nothing happened.

“Generally, you need to stab someone with it for it to work,” Raboniel said. “You need to touch the soul.”

Navani nodded absently, resetting her equipment with the tuning fork and the magnifying lens, then watching the spren inside move to the sound. She set the tip of the dagger against it again, watching for any different behavior.

“You seem to be enjoying yourself,” Raboniel noted.

“I would enjoy myself more if my people were free, Lady of Wishes,” Navani said. “But I intend to use this time to some advantage.”

Their defense of the tower, frail though it was, had utterly collapsed. She couldn’t reach Kaladin, hear the Sibling, or plan with her scholars. There was only one node left to protect the heart of the tower from corruption.

Navani had a solitary hope remaining: that she could imitate a scholar well enough to build a new weapon. A weapon to kill a god.

In her experiment, nothing happened. The spren couldn’t get out of the ruby, even with the tone calling it. The spren was vivid blue, as it was corrupted, and appeared as half a spren: one arm, one leg. Why continue to manifest that way? Flamespren often changed forms—and they were infamous for noticing they were being watched. Navani had read some very interesting essays on the topic.

She picked up a small jeweler’s hammer. Carefully, she cracked the half ruby, letting the spren escape. It sprang free, but was immediately captured by the dagger. Light traveled along the blade, then the ruby at the base began to glow. Navani confirmed that the half spren was inside.

Interesting, Navani thought. So, what if I break the other half of the ruby and capture that half in the same gemstone? Excited, she reached to grab the other half of the ruby—but when she moved it, the dagger skidded across the table.

Navani froze. The two halves of the spren were still conjoined? She’d expected that to end once the original imprisonment did. Curious, she moved the dagger. The other half of the ruby flew out several feet toward the center of the room.

Too far. Much too far. She’d moved the dagger half a foot, while the paired ruby had moved three times as far. Navani stared at the hovering ruby, her eyes wide.

Raboniel hummed a loud rhythm, looking just as startled. “How?” she asked. “Is it because the spren is corrupted?”

“Possibly,” Navani said. “Though I’ve been experimenting with conjoined spren, and corrupted ones seem to generally behave the same as uncorrupted ones.” She eyed the dagger. “The gemstone on the dagger is larger than the one it was in before. Always before, you had to split a gemstone in two equal halves to conjoin them. Perhaps by moving one half to a larger gemstone, I have created something new.…”

“Force multiplication?” Raboniel asked. “Move a large gemstone a short distance, and cause the small gemstone to go a very long one?”

“Energy will be conserved, if our understanding of fabrial laws is correct,” Navani said. “Greater Light will be required, and moving the larger gemstone will be more difficult in equivalency to the work done by the smaller gemstone. But storms … the implications…”

“Write this down,” Raboniel said. “Record your observations. I will do the same.”

“Why?” Navani asked.

“The Rhythm of War, Navani,” Raboniel said as an explanation—though it didn’t seem one to Navani. “Do it. And continue your experiments.”

“I will,” she said. “But Lady of Wishes, I’m running into another problem. I need a way to measure the strength of Stormlight in a gemstone.”

Raboniel didn’t press for details. “There is sand that does this,” she said.

“Sand?”

“It is black naturally, but turns white in the presence of Stormlight. It can, therefore, be used to measure the strength of Investiture—the more powerful the source of power nearby, the quicker the sand changes. I will get some for you.” She hummed loudly. “This is amazing, Navani. I don’t think I’ve known a scholar so capable, not in many Returns.”

“I’m not a…” Navani trailed off. “Thank you,” she said instead.