Byleth wrinkled her nose as she opened the stone door and smelled the noxious wind coming from the other side. She could count on one finger the number of times she had come down here into the nadir of her palace, and she wouldn't have done it tonight except that she was too angry to wait for him to come to her.

Leaving her soldiers outside, she led Xantu and Gilgar down the long, winding tunnel into the earth. The walls were rounded and almost smooth with a faint reflective sheen. Despite the glowing red runes inscribed on the tunnel ceiling every twenty paces to stifle the intense heat that flowed up from the depths of the earth, the walls and floor were still hot enough to burn bare skin. She held onto a trickle of zoana to maintain a halo of coolness around herself, and not a hint of perspiration dampened the sheer silk of her dress.

Three men bowed as she passed them at an intersection of two tunnels. Lord Astaptah's minions were uniformly thin to the point of emaciation, and they all wore the same ash-gray robe that matched their complexions. They never spoke within her hearing, and it occurred to Byleth that she didn't know much about what went on down here. When Lord Astaptah had first come to her with his ideas, she needed a place to keep him close but out of sight. These lava tubes under the palace had seemed like the perfect solution.

She entered the main chamber and nearly choked at the powerful stench of brimstone that billowed around her. Air currents rising from the moat of red-hot magma below played with her hair. Seven figures stared down from the shadows obscuring the chamber's ceiling—seven massive statues carved from the basalt walls. Their visages were hidden within deep stone cowls, but Byleth could swear their invisible eyes followed her. She had always been skeptical of the existence of the gods and their effect on her daily life, despite the religious training that had been drilled into her head as a child. Yet she recalled being nervous when Astaptah built this hidden shrine to the seven demon-lords of the underworld. She had stood in this chamber right after its construction, with Lord Astaptah standing before her holding a red candle and a copper dagger, lifting the implements to the statues as he chanted in his native tongue. Looking back now, Byleth wondered why she had participated in the ritual. Astaptah had said it was necessary to seal their pact. She also remembered being desperate for a means to escape her fate.

Not much has changed since then.

A drop of sweat ran down Byleth's left cheek, despite her enchantment.

Comforted by the presence of Xantu and Gilgar behind her, she descended the metal catwalks. The tall chamber didn't have a floor. Instead, a pool of magma bubbled and churned around an island of rock rising from its center. Lord Astaptah stood on the isle, working on the machine occupying most of its area. A glittering stone hovered over his shoulder. Looking like a sliver of onyx, it radiated a fierce blue light.

Stepping across the narrow stone bridge, Byleth called out to him, “You had better have a good explanation.”

Astaptah turned around, holding a long metal rod. Its tip glowed cherry red. “I am busy. If this can wait—”

She strode up and slapped the rod out of his hand. “This will not wait. Do you realize that I was almost killed tonight?”

He drew himself up to his full height, looming over her. A powerful odor of acerbic chemicals flooded Byleth's lungs. Her bodyguards came up to flank her.

“I have been preoccupied,” Astaptah said. The floating onyx stone hung in the air between them, rotating slowly.

Byleth gestured to the metal construction above them. The storm engine was displeasing to the eye, all girders and connecting struts, lacking the graceful lines that she demanded from all things in her presence. Thick cables ran from the apparatus to the chamber walls, disappearing into the stone. She remembered the day when Lord Astaptah, not long after his near-fatal journey across the southern desert, had come to her with a proposal, that she give him the means to build this metal monstrosity. Through it, he had promised, she would become the most powerful ruler in Akeshia. For the daughter of a king who had failed in his own bid to win the Chalcedony Throne, the chance to do what her father had not was irresistible.

“You told me your contraption would protect Erugash from these storms,” she said.

“It did better than that,” he said. “The engine achieved terminal charge fifty-eight minutes before true midnight.”

Byleth bit off a bitter retort as his words penetrated her wrath. That time corresponded with the appearance of the chaos storm over the city. “Are you saying that you created the storm?”

Astaptah's eyebrows came together in an ugly frown. “Not precisely. A storm front was moving through the area when the engine became active. The atmospheric activity presumably aided in the—”

“Don't babble,” she said. “Just tell me. Did your machine create that storm or not?”

“In a sense…yes.”

The ember of hope she had long sheltered in her heart burst to new life, eclipsing the anger she'd felt just moments ago. “What went wrong?”

“When the surge struck, the etheric distributor went into a systemic feedback loop that…”

Byleth tried to follow his torturous explanation of the night's events, but all she was able to glean was that the chaos storm had broken Astaptah's machine, and he was endeavoring to repair it. She lifted a hand. “Spare me any more details. You say you can fix it?”

“Of course, though it will take time. Time better spent than talking with you—”

“Watch your tongue,” Xantu said in a low whisper.

“Or you might lose it,” Gilgar added with a mocking smile.

Astaptah glanced at them with an expression devoid of any emotion, like they were a pair of insects who had just crawled up his arm, and Byleth almost reached for her zoana. As it was, she felt the twins seething with the desire for violent release. She stilled them with a wave of her hand.

The vizier turned once again to face his creation. “I also told you that this is not a precise science. However, I, too, am puzzled. The engine should have been insulated from any harm. It's almost as if…”

She edged closer. She needed to know if this was truly the breakthrough she had been waiting for, the key to the gambit that might save her life and her crown. “As if what?”

Astaptah picked up the rod from the floor. Its tip had cooled to an orange glow. “It's as if a stronger force had overridden the power of the storm. But it is difficult to countenance. It would have had to be more power than a dozen zoanii of the first rank bound together in a single stroke.”

Byleth bit her bottom lip. “I may have your explanation. When the storm struck, I took all the zoanii I could lay hands upon and tried to deflect the storm away from the city. I had no idea what you were doing down here. If I'd known, I would have…”

What? Let my city be destroyed so that Astaptah could demonstrate his toy?

“And you were successful?” he asked.

“Actually, yes. Against all odds, we dispelled the storm entirely. It was quite amazing. I don't know if another cabal in recent times could have done it.”

Astaptah was studying her with his deep, amber eyes. She didn't like feeling them upon her for any extended period, especially down here in his sanctum.

“A bold maneuver,” he said.

Was that sarcasm in his voice? She longed to rake out his eyes with her fingernails. Then she thought back to the storm. She could still feel the rain driving into her body, hear the wind drowning out her thoughts, and the incredible power of the cabal flowing through her. Yet the storm had defied them. She'd been on the verge of giving up before the effort killed her when a sudden explosion of power shattered her concentration. She saw Horace in her mind, his head thrown back in an imitation of agony or ecstasy. And then the storm was gone.

“He saved us.”

“Majesty?”

Byleth frowned. Astaptah never referred to her royal status unless he wanted something. “The savage,” she said.

His eyes came alight as if he had been dozing up until this point and was only now coming fully awake. “The foreigner? What did he do?”

“I'm not entirely sure.” Byleth wasn't sure how much to tell him. She'd never fully trusted Astaptah and saw no reason to change that now. “His zoana is exceptionally strong, but he has no control over it. It leaps and jumps about like the Typhon in flood season, overflowing its channel and washing away everything in its path.”

“Interesting,” Astaptah murmured, but he no longer seemed to be listening.

“What are you going to do about it?”

The vizier turned back to his work. The end of the rod flared to life with a yellow gleam. “The foreigner is your concern.”

That was most certainly true. She could not deny his allure. She'd had lovers aplenty, but there was something different about Horace. He was exotic, of course, and there was the added element of his power. Normally, she would just send for him and have her way, but she hadn't done that with this foreign shipbuilder-turned-zoanii, and the reason why escaped her. Her father had always encouraged her to take whatever she wanted in life. A true king, or queen, he'd said, does not ask for anything. He takes it, or he lives without it. Asking is for lesser mortals.

Yet some part of her was afraid that if she sent for Horace, he would deny her. Oh, he could not hide his obvious attraction to her, but there was also something else in his gaze when he looked at her, a touch of reservation she had never encountered before. She was a queen. Men would lay down their lives at her whim, but this savage with the sea-green eyes was different. If she wanted him, she would have to offer more than just her favors. But a queen did not bargain, and thus she was caught in an achingly delicious trap. And then there was the matter of the foreign attack on her city. Horace couldn't be involved, could he?

“Forget him,” she said, unable to keep a slight growl from her voice. “You promised to deliver the empire to me.”

“And so I shall.”

“When?”

“In due time. This is no simple task. We will have only one chance for success. It needs to be timed with perfection.”

She stepped toward him, her hands clenched at her sides. “My enemies are moving against me. I can feel them breathing on the back of my neck, and Ceasa seems farther away now than on the day I saved you.”

“I am not the weakling you found on your doorstep,” he said, not bothering to look back at her. “I serve you of my own free will and for my own purposes.”

“But you do serve me, Astaptah. Never forget that.”

“I would never dream of it.”

She glanced up at the machine, its silver bars gleaming dully in the gloom. “I want it ready in three days, Astaptah. Or I'll come back to take your head as recompense. Do you understand?”

“I do.”

“Good. Now I wish to see him.”

Astaptah set down the rod on a metal box. “As you wish.”

Followed by the floating stone, he led her back across the bridge and through a wide tunnel. It sloped downward, taking them deeper underground as it twisted in a slow curve. Byleth was glad she'd decided to bring the twins. She had never feared for her own safety before—her training and strength in the Imuvar dominion was unequalled in the city—but there was something about these catacombs that unnerved her.

Byleth gestured for the twins to remain outside as Astaptah ushered her into a chamber carved from the living stone. The only furnishing was an upright slab of gray stone positioned against the far wall under an array of wires and cables that extended up into the ceiling, leading—she knew—to the storm engine. By the stark light of the onyx stone, Byleth observed the man on the slab. His muscular body and limbs were bound in wide bands of zoahadin. His eyes were bruised purple and black around his closed lids. Dried blood stuck to a circular cut on his forehead.

It was funny. She'd known him all her life, and yet she had never understood him as well as she did now. “Zazil, can you hear me?”

Her brother opened his eyes. He tried to speak, but only a groan issued from his lips, which had been sewn together. His arms and legs twitched within their zoahadin binders, but that was the limit of his movement.

“So how does this work?” she asked.

Astaptah came over to stand on the other side of the table. “It is, in essence, a zoana pump.”

For years Astaptah had been demanding proper subjects for his work. She had heard his accounts of trying to use livestock, but people produced the best results. Criminals, dissidents, and the undesirables of society had all been assigned to her chief vizier's less-than-tender mercies, but it wasn't until he chanced upon a victim—a young leper girl, if she recalled correctly—with latent magical talent that his experiments took a turn for the better.

While Astaptah explained how the machine would slowly drain her brother of his zoana, Byleth studied Zazil's face. This was her flesh, her blood. She could read the question in his gaze. Could she really let him die this way? She leaned down so she could look into his eyes.

“Of course I can, brother.” She ran her hand across his bare stomach. “There is a price for betrayal.”

Zazil shook his head violently, and Byleth placed a finger over his sewn lips to still him. “Don't bother denying it. I know all about your dealings with the Temple of Amur. You've been jealous of my birthright since we were children. I hoped you had outgrown it, but it seems you have given me no choice.”

Astaptah hunched over a panel of metal levers against the wall. Each lever was marked with an unfamiliar icon, possibly derived from his native alphabet. He took a long metallic hose from a hook on the wall. Its open end was surrounded by sharp prongs like teeth, which he placed upon Zazil's forehead. An ominous hum emanated from the cable, and her brother arched up from the slab like a puppet pulled by its strings. An animalistic growl emanated from his sealed mouth. Byleth could feel the presence of zoana above her like an invisible sun, bathing her in its radiance. “How long will he last?”

“The prince is young and strong,” Astaptah replied. “It may take days to drain him completely.”

Watching her brother's contortions, she tried to imagine living in such agony for hours and days on end. “Yes. He was always strong. How did you manage to take him alive? Poison? Treachery?”

“I enjoyed a stroke of good fortune, Majesty.” Astaptah reached over to adjust a lever. “And proper timing.”

Byleth watched the way her brother's eyes strained in their sockets. It wasn't just the torment he was suffering; Zazil was terrified of her vizier. She stored that information away. “I have delivered my end of the bargain, my lord. You have your ‘perfect specimen.’ You have three days to deliver on your promise.”

Astaptah turned to her, his face perfectly smooth. “Once I have calibrated the engine to accept the new levels of power, I believe we shall be ready.”

Byleth stepped closer to her vizier, even as her intuition cried out for caution. “And I'll be able to direct the storms however I wish? At any time?”

“Yes. However and whenever. Their power will be yours to command.”

No army will be able to stand against me. Every city in the empire will open its gates to me.

“Don't disappoint me, Astaptah. My patience is coming to an end.”

The door of the chamber opened, and one of the vizier's robed minions entered on silent footsteps. The wizened man stole over to Astaptah's side and whispered something. Byleth frowned. She didn't like people whispering in her presence. After a few seconds, the servant departed.

“What is it?” Byleth asked.

“Omikur has fallen to the crusaders.”

Byleth fought the urge to smash something. The air whipped around her in a tiny whirlwind until she regained control. Omikur was a major trading hub and one of the most important towns in the western desert. She could not afford to let it go without a fight, for her brother kings would view it as a sign of weakness.

A ragged howl rang out through the chamber. Byleth frowned, her thoughts disturbed. Zazil had burst his lip sutures and was wailing like a starving infant.

“I need your engine to work,” she said. “Now.”

Astaptah's eyes glared from beneath their heavy lids as he nodded. “As you wish. The risk will be yours.”

With a glare at him, she headed out the door to find out what had happened and how she might remedy the situation. The twins fell in behind her without a word.

As she strode out of the sweltering chamber, Byleth mused that this disaster couldn't have come at a worse time. Her court would need reassurance that she was in command of events. Then there was the question of Horace. How should she handle him? Part of her recognized the danger of allowing him to live. Like any weapon, he could be turned against her. Yet what if he had been sent to her by the gods? Could she risk eliminating a possible chance at victory?

Followed by the wails of her brother, she ascended back to the world above.