She failed.

She couldn’t get Stormlight and Lifelight to mix. No use of tuning forks, no touching of the streams or clever use of gemstone differentials, worked.

She tried mixing Voidlight and Lifelight. She tried mixing all three. She tried every experiment she’d listed in her brainstorming sessions earlier. Then she did them all again, until—because each experiment allowed a little Lifelight to vanish into the air—she’d used it all up.

Shooing away exhaustionspren, she stood, frustrated. Another dead end. This was as bad as the morning’s experiments, when she’d tried everything she could think of—including using two tuning forks at once—to make Towerlight move from its gemstone. She’d failed at that as well.

She gathered all the used diamonds and deposited them by the door guard to be picked up and reinfused—there was a highstorm coming today. After that, she paced, frustrated. She knew she shouldn’t let the lack of results bother her. Real scientists understood that experiments like this weren’t failures; they were necessary steps on the way to discovery. In fact, it would have been remarkable—and completely unconventional—to find a good result so early in the process.

The problem was, scientists didn’t have to work under such terrible deadlines or pressures. She was isolated, each moment ticking them closer to disaster. The only lead she had was in trying to mix the Lights, in the hope that she could eventually create more Towerlight to help the Sibling.

She wandered the room, pretending to inspect the spines of books on the shelves. If I make my discovery, Raboniel will know, since a guard is always watching. She’ll force the answer out of me, and so even in these attempts to escape, I’m furthering her goals—whatever those are.

Navani was on the cusp of something important. The revelations she’d been given about Stormlight fundamentally changed their understanding of it and the world at large. Three types of power. The possibility they could be blended. And … possibly something else, judging by that strange sphere that warped the air around it.

Her instincts said that this knowledge would come out eventually. And the ones who controlled it, exploited it, would be the ones who won the war.

I need another plan, she decided. If she did discover how to make Towerlight, and if the shield did fall, Navani needed a way to isolate the crystal pillar for a short time. To defend it, perhaps to work on it.

Navani gripped her notebook in her safehand, to appear as if she were writing down the titles of books. Instead she quickly took notes on an idea. She’d been told she could have anything she needed, so long as it was relevant to her experiments. They also let her store equipment out in the hallway.

So, what if she created some fabrial weapons, then stored them in the hallway? Innocent-looking fabrials that, once activated, could be used to immobilize guards or Fused coming to stop her from working on the pillar? She sketched out some ideas: traps she could create using seemingly innocent fabrial parts. Painrials to administer agony and cause the muscles to lock up. Heating fabrials to burn and scald.

Yes … she could create a series of defenses in the form of failed experiments, then store them “haphazardly” in crates along the hallway. She could even arm them by using Voidspren gems, as she could demand those for use in her experiments.

These plans soothed her; this was something meaningful she could do. However, the experiments, and their potential, still itched at her. What was Raboniel’s true goal? Was it to make a weapon herself—like the one that had destroyed the room and Navani’s two scientists?

A few hours had passed, so it wouldn’t look strange if she went to the back of the stacks again. She picked up a book and settled down in a chair she’d placed nearby. Although she wasn’t directly visible to the guard, she pretended to read as she reached her hand to the wall and touched the vein.

“Any spren nearby?” Navani asked.

I cannot feel any, the Sibling said with a resigned tone.

“Good. Tell me, do you know anything of the explosion that happened on the day of the invasion? It involved two of my scientists in a room on the fifth floor.”

I felt it. But I do not know what caused it.

“Have you ever heard of a sphere, or a Light, that warps the air around it? One that appears to be Voidlight unless you look at it long enough to notice the warping effect?”

No, the Sibling said. I’ve never heard or seen anything like that—though it sounds dangerous.

Navani considered, tapping her finger against the wall. “I haven’t been able to get any of the Lights to mix. Do you know of any potential binding agent that could make them stick together? Do you know how Towerlight is mixed from Stormlight and Lifelight?”

They don’t mix, the Sibling said. They come together, as one. Like I am a product of my mother and father, so Towerlight is a product of me. And stop asking me the same questions. I don’t care about your “investigative methods.” I’ve told you what I know. Stop making me repeat myself.

Navani took a deep breath, calming herself with effort. “Fine. Have you been able to eavesdrop on Raboniel at all?”

Not much. I can only hear things near a few people that are relevant. I can see the Windrunner. I think the Edgedancer has been surrounded by ralkalest, which is why she’s invisible. Also, I can see one particular Regal.

“Any ideas on why that is?”

No. Regals weren’t often in the tower in the past, and never this variety. She can speak all languages; perhaps this is why I can see near her. Though she vanishes sometimes, so I cannot see all she does. I can also see near the crystal pillar, but with the field set up, I hear mere echoes of what is happening outside.

“Tell me those, then.”

It’s nothing relevant. Raboniel is trying her own experiments with the Light—and she hasn’t gotten as far as you have. This seems to frustrate her.

Curious. That did a little for Navani’s self-esteem. “She really wants this hybrid Light. I wonder … maybe fabrials made with a hybrid Stormlight-Voidlight would work in the tower, even if the protections were turned against her again. Maybe that is why she wants it.”

You are foolish to presume to know what one of the Fused wants. She is thousands of years old. You can’t outthink her.

“You’d better hope that I can.” Navani flipped a few pages in her notebook. “I’ve been thinking of other ways out of this. What if we found you someone to bond, to make them Radiant? We could—”

No. Never again.

“Hear me out,” Navani said. “You’ve said you’ll never bond a human again, because of the things we do to spren. But what about a singer? Could you theoretically bond one of them?”

We are talking of resisting them, and now you suggest I bond one? That seems insane.

“Maybe not,” Navani said. “There’s a Parshendi in Bridge Four. I’ve met him, and Kaladin has vouched for him. He claims that his people rejected the Fused long ago. What about him? Not a human. Not someone who has ever created a fabrial—someone who knows the rhythms of Roshar.”

The Sibling was silent, and Navani wondered if the conversation was over. “Sibling?” she asked.

I had not considered this, they said. A singer who does not serve Odium? I will need to think. It would certainly surprise Raboniel, who thinks that I am dead or sleeping.