“Have you written this down?”

“No, I’ve merely been toying with random ideas.”

“A lie you must tell,” Raboniel said. “I do not begrudge you it, Navani. But know that I will rip this room apart to find your notes, if I must.”

Navani remained quiet, meeting Raboniel’s gaze.

“Still you do not believe me,” Raboniel said. “That we are so much stronger when working together.”

“How could I trust your word, Raboniel?” Navani said. “You’ve already broken promises to me, and each time I’ve asked to negotiate for the benefit of my people or the Sibling, you’ve refused.”

“Yes, but haven’t I led you to a weapon?” she asked. “Haven’t I given you the secrets you needed to make it this far? Within reach of something that could kill a god? All because we worked together. Let’s take this last step as one.”

Navani debated. She knew that Raboniel wasn’t lying; the Fused would rip this room apart to find Navani’s notes. Beyond that, she’d likely take away Navani’s ability to requisition supplies—halting her progress.

And she was so close.

With a sigh, Navani crossed the room and took her notebook—the one they’d named Rhythm of War—from a hidden spot under one of the shelves. Perhaps Navani should have kept all of her discoveries in her head, but she’d been unable to resist writing them down. She’d needed to see her ideas on the page, to use notes, to get as far as she had.

Raboniel settled in to read, to learn what Navani had discovered about this new tone—humming a rhythm of curiosity to herself. A short time later, a servant arrived at the door carrying a large wooden box.

“At last.” Navani stepped over, taking the box from the servant. Inside was a glass tube a little less than a foot in diameter, though it was several feet long, with thick metal caps on the ends.

“And that is?” Raboniel asked.

“A Thaylen vacuum tube,” Navani said. “From the Royal Institute of Barometric Studies. We had this device near the top floor of the tower, where we were doing weather experiments.”

She set the device down and took the notebook back from Raboniel, making a few notations to start her next experiment. The metal caps could be unscrewed to reveal chambers that, with the seals in place, wouldn’t disturb the vacuum in the central glass chamber. She opened one end, then affixed an empty diamond into it. Next she used her jeweler’s hammer to crack a gem full of Voidlight—which made it start to leak. She quickly affixed it into the berth on the other side of the vacuum tube. She redid the ends, then used a fabrial pump to remove the air from the side chambers.

Finally, she undid the clasps that sealed the side berths, opening them to the central vacuum. If she’d done everything correctly, little to no air would enter the central glass chamber—and she now had a gemstone on either end.

Raboniel loomed over Navani as she observed the Voidlight floating out into the vacuum. It didn’t act as air would have—it wasn’t pulled out, for example. Whatever Voidlight was, it didn’t seem to be made up of axi. It was an energy, a power.

“What are we doing?” Raboniel asked softly.

“I believe this is the only way to completely separate Voidlight from the songs of Roshar,” Navani explained. “There can be no sound in a vacuum, as there is no air to transfer the waves. So as this gemstone ejects Voidlight, I’m hoping the Light will not be able to ‘hear’ Odium’s rhythm—for the first time in its existence.”

“You think it doesn’t emit the rhythm itself,” Raboniel said, “but echoes it. Picks it up.”

“Like spren pick up mannerisms from humans,” Navani said. “Or how a piece of metal can be magnetized by touching a magnet over a long period of time.”

“Ingenious,” Raboniel whispered.

“We’ll see,” Navani said. She grabbed her bow, then pressed the plate against the side of the vacuum chamber and began playing her anti-Voidlight tone.

Raboniel winced at the sound. “The Light won’t be able to hear,” she said. “It’s in a vacuum, as you said.”

“Yes, but it’s moving across, and will soon touch the empty diamond at the other side,” Navani said. “I want this to be the first thing it hears when it touches matter.”

They had to wait a good while as the Voidlight drifted in the vacuum, but Navani kept playing. In a way, this was the culmination of her days of fervor. The climax to the symphony of madness she’d been composing.

Voidlight eventually touched the empty diamond and was pulled inside. She waited until a good measure of it had been drawn in, then had Raboniel undo the clasp separating the diamond’s enclosure from the vacuum. Navani opened this to a little pop of sound, then plucked out the diamond. It glowed faintly violet-black. She stared at it, looking closer, until …

Yes. A faint warping of the air around it. She felt a thrill as she handed it to Raboniel—who screamed.

Navani caught the diamond as Raboniel dropped it. The Fused pulled her hand to her breast, humming violently.

“I take it the sound wasn’t pleasant,” Navani said.

“It was like the tone that plate makes,” Raboniel said, “but a thousand times worse. This is a wrongness. A vibration that should not exist.”

“It sounds exactly the same as the tone of Odium to me,” Navani said. She set the gemstone on her desk beside the dagger Raboniel had given her. The one that could channel and move Light.

Navani sat in the chair beside it. Raboniel joined her, moving a stool from beside the wall. Together, both of them stared at the little gemstone that seemed so wrong.

“Navani,” Raboniel said. “This … This changes the world.”

“I know,” Navani said. She rubbed her forehead, sighing.

“You look exhausted,” Raboniel noted.

“I’ve barely slept for days,” Navani admitted. “Honestly, this is all so overwhelming. I need a break, Raboniel. To walk, to think, to gather my wits and get my blood moving again.”

“Go ahead,” Raboniel said. “I’ll wait.” She waved for the guard to go with Navani, though the Fused herself continued staring at the gemstone. In fact, Raboniel was so fixated on the diamond that she didn’t notice Navani take Rhythm of War as she stepped out with the guard into the hallway.

She braced herself. Expecting …

An explosion.

It shook the corridor, striking with such physical force that Navani’s guard jumped in shock. They both spun around to see smoke spewing from the room they’d left. The guard rushed back—grabbing Navani by the arm and hauling her along.

They found chaos. The desk had exploded, and Raboniel lay on the floor. The Fused’s face was a mask of pain, and her front had been shredded—her havah ripped apart, the carapace scored and broken, the skin at her joints stuck with pieces of glass. Or diamond? She hadn’t taken much shrapnel to the head, fortunately for her, though orange blood seeped from a thousand little wounds on her arms and chest.

At any rate, Raboniel was still alive, and Navani’s scheme had failed. Navani had assumed that, in her absence, Raboniel would take the next step—to try mixing Voidlight with the new Light. Raboniel kept saying she expected the Lights to puff away when mixed, vanishing. She didn’t expect the explosion.