Who were these people?
Felix couldn't make out their faces. From head to toe, they were wrapped in black cloth—figures of stark contrast against the golden sands. Their movements were light, precise, and graceful—far too refined for ordinary Sarkaz mercenaries.
No… they moved like assassins.
He noticed something odd: the moment these black-clad figures approached the Rhodes Island, they didn't attack. Instead, they silently followed its path, matching its movement, like shadows trailing their prey.
Felix had never heard of a department like this within Babel—something akin to the "Dark Guard" one might read about in novels. He'd never asked Theresa about it, and Kal'tsit wasn't by his side now. The Doctor's communication line was one-way, so even if he wanted to ask, no one could reply.
With no answers to be found, he quietly shelved his curiosity.
He directed his drones to continue surveillance, then returned his focus to cleaning up the battlefield.
The western gate had been defended by Goliath mercenaries, but Felix also spotted several Vampire officers among them. Their Originium Arts were tied to the manipulation of blood—dangerous and violent—but in the face of Babel's overwhelming numbers, they were quickly surrounded. They didn't last long before surrendering, stripped of any will to resist.
The city gate stood wide open. The western entrance had fallen first.
When ACE's squad entered, they found Felix speaking with a Sarkaz woman—white-haired, red-horned, and visibly irritated. They didn't interrupt, waiting until the woman—W—stormed off, muttering curses under her breath.
"Hope I didn't interrupt," ACE said casually.
"Not at all," Felix replied. "W just wanted to talk about the battle. Her vanguard mission's done, but she insisted on staying behind to plant explosives. I sent her to Kal'tsit."
"…Explosives?"
ACE paused for a moment, then quickly shifted topics. "Let's hope things go smoothly on Scout's side."
"Don't worry. Doctor Kal'tsit's in charge of that gate."
"Good. Then we're clear."
Side by side, Felix and ACE advanced toward the heart of the city. To the north stood the Military Committee's grand assembly hall—and in front of it, lines of mercenaries gripped their weapons in silence. Clearly, there'd be no entering the hall without cutting them down first.
Kazdel's mobile city felt fragmented, disorganized—more like a crumbling shell than a fortress.
To be honest, Felix felt a pang of disappointment. So far, the strongest foe he'd faced was merely a Vampire commander. Hopefully, the hall's defenders would provide something more… satisfying. Otherwise, this conquest would become unbearably dull.
"This was all part of the Doctor's plan," ACE explained, noting Felix's expression. "He noticed that most of the Military Committee's elite units had left the city. That's why he orchestrated this sudden strike."
ACE adjusted his sunglasses, a grin tugging at his lips.
"According to the Doctor's calculations, we'll have complete control of Kazdel's mobile city in two hours."
"Logos—take care of the caster division," he ordered into his comms.
A young, almost ethereally handsome man gave a curt nod. His face betrayed no emotion. He inclined his head politely toward Felix before leading a team toward the city center.
"Logos is a young banshee," ACE explained as they walked. "His task is to pacify the central residents. Many of them have taken up arms after our assault, and Logos… well, he'll convince them. With spells."
"…I think I've seen him before," Felix said thoughtfully. "In the Frontier District."
"That wouldn't surprise me," ACE chuckled. "He mentioned staying here in Kazdel's mobile city for a while before taking a little vacation in a 'fresh new place.' Said he liked the coffee there. And as far as I know, the only place with coffee shops in all of Kazdel… is your Frontier District."
"I've heard from some adventurers there," Felix added, "that he wasn't alone. There was an older female banshee with him."
"That, I don't know."
ACE scratched his head. "We don't really understand much about the banshee clans. But if you're curious, you can ask him directly. He may look cold and serious, but trust me—he once organized office chair races in the command room. Also, he reads compilations of bad jokes with a straight face."
He spread his hands helplessly. Felix couldn't help but smile.
Then, his expression cooled, his tone turning measured and serious.
"ACE," he said, eyes narrowing slightly, "as a senior officer of Babel… do you know if there's a covert division within—something like an assassination or shadow unit?"
ACE's expression hardened. He shook his head gravely.
"I've never heard of such a thing. Her Highness would never authorize something like that—you know her as well as I do."
"But then… why have I been seeing these black-clad assassins tailing the Rhodes Island since earlier?"
ACE removed his sunglasses and leaned closer to the holographic screen projected from Felix's wrist. The moment his eyes caught sight of the figures, his face darkened.
"These aren't Babel operatives. They're… assassins."
"Assassins?" Felix's tone was calm, but his gaze sharpened.
ACE straightened, his voice low and tense. "Felix, can I trust you?"
Felix met his eyes. "I trust you—just as you trust me."
ACE exhaled slowly. "Then listen carefully. These people aren't from Babel. I suspect… we've got a mole."
He spoke in a hushed tone, gesturing subtly for his squad to move ahead. When they were alone, he pulled Felix into a narrow alleyway between the ruins.
"This entire operation was supposed to be a top-secret offensive," ACE whispered. "Every mercenary mobilized here belongs directly to Babel. We didn't hire anyone from the Scars Market or the neutral guilds we usually partner with."
"When exactly was this war plan relayed to the ranks?" Felix asked.
"Four days ago."
"Four days…" Felix rubbed his chin, thinking aloud. "Then it's unlikely a lower-ranked leak. My drones spotted over a hundred assassins cloaked in black already. There's no way they could've gathered that many people in just four days unless…"
"…unless someone high up leaked the plan early," ACE finished grimly. His voice was dry, strained. "A traitor… among the upper echelons?"
"Yes. And whoever it is, they must have known about the operation long before it was announced."
Felix's voice lowered, his words deliberate. "These assassins appeared on the very route Rhodes Island was taking—and that's classified information. No common mercenary could've known that."
"Who could it be…?" ACE muttered through clenched teeth. Faces of his comrades flashed in his mind—people he'd fought beside, bled beside. Yet now, those familiar faces twisted into cold, distant smirks, mocking his loyalty. The thought of betrayal hit him like a blade to the gut.
"Speculating won't help us now," Felix said quietly. "They haven't made a move against Babel yet, so we proceed with the current plan. But ACE… in the meantime, think carefully. Among the high command—who stands to gain the most from betrayal?"
ACE fell silent. His fists trembled at his sides. Doubting his comrades was agony; the weight of it pressed against his chest until he could barely breathe.
"Her Highness is in danger," he finally hissed. "We should return immediately—to protect her."
"If we go back now," Felix countered softly, "the traitor might catch wind of it—and strike first."
His eyes swept across the nearby streets, where confused Kazdel civilians peeked from shattered windows, unaware of the war swirling around them.
"When we've secured full control of the city," Felix continued, "I'll return to Rhodes Island ahead of the others—with my squad. What about you, ACE?"
"I'm going with you."
Felix turned his head slightly, studying him. ACE offered a bitter smile.
"What? Don't you trust me?"
"I do," Felix said simply.
ACE took a deep breath, his voice low. "Have you told anyone else about this?"
"…No. Right now, I only trust you—and Doctor Kal'tsit."
Felix's tone was measured, calm. "If the mole really is among the upper ranks, it's too risky to spread the word. Besides, I'm not a Babel officer or mercenary. I'm hardly in a position to raise the alarm myself."
Neither man spoke further as they left the alley and returned to the city center, where Doctor Kal'tsit awaited them.
Beside her stood a tall Sarkaz man, face half-hidden behind a mask, about thirty-four years old, a long rifle slung across his back.
The sight was rare—Sarkaz carrying a firearm could mean only one thing: it had been taken from a Sankta.
Scout wasn't the only one; even the infamous mercenary W carried a confiscated gun of Sankta make—though, unlike Scout, she preferred to solve her problems with bombs.
Before them stood an enormous boiler rising into the air. Looking up, Felix couldn't even see the top — it stretched endlessly upward, like the central furnace in Frostpunk, burning energy to sustain the city's very life.
This one — or rather, this energy well — served the same purpose, fueling the colossal engine that kept Kazdel's mobile city moving across the wasteland.
"Up ahead is the Parliament Hall," Scout said, his hands casually stuffed into his pockets. "It used to be the seat of both the Babel and the Military Council, where Her Highness and the General ruled together."
"The Council's army is already waiting for us," he added. "But… they won't be a match."
Dr. Kal'tsit turned her face slightly, murmuring something into her earpiece to Mantra before giving the order:
"Advance on the Parliament Hall."
"Yes, ma'am."
The army began its silent march forward. Felix walked beside ACE, deep in thought — trying to piece together who could have leaked Babel's movements.
From what he could tell, it couldn't have been Kal'tsit. Despite her cold expression, she had no ill will toward Her Highness. ACE, though Felix hadn't known him in his previous life, simply didn't seem capable of betrayal. His steady, protective presence was too genuine.
As for the Sarkaz mercenaries, that was even less likely. Their loyalties were decided from the very beginning. It was impossible that a Sarkaz spy had climbed into the upper ranks — not with so many sharp-eyed Sarkaz watching for exactly that kind of threat.
His train of thought was cut short by the sight of blood pooling on the floor.
ACE instinctively raised his shield to cover him as Hoederer and Jesselton charged ahead, clashing with a group of mixed-race Sarkaz mercenaries. Mudrock swung her massive hammer, standing guard in front of Felix, while Ines slipped into his shadow, a dagger gleaming in her hand.
"Commander!"
A Vampire caster shrieked from the enemy ranks. Dozens of crimson spheres appeared in the air, pulsing ominously before exploding. Scarlet liquid splattered across Babel's soldiers — those it touched screamed in agony. The substance was clearly corrosive.
"Give up, Zosia. Your resistance won't bring you victory," Scout said calmly, lifting his rifle.
He paused. "Drop your staff."
The Vampire caster, Zosia, sneered. "When the General left this place, I had already accepted my fate—"
A deep, guttural chant spilled from his mouth, and the blood orbs swelled, trembling on the verge of collapse.
A dark sigil flared beneath his feet — a binding spell slowing his movements.
A shadow flickered.
A blade pierced through Zosia's chest.
"…The General treated you well, Ascalon."
Ascalon said nothing. She withdrew her dagger silently and glanced toward Logos, who stood behind her with his spell-engraved pen raised. She gave him a small nod of thanks.
Kal'tsit wasted no words.
"Take the Parliament Hall."
The mercenaries surged forward as one, blades flashing under the crimson light.
"I never expected you to be the one making the biggest impact in this siege," a familiar voice drawled.
W had appeared beside Felix at some point, her tone mocking but tinged with surprise.
"You did well too, W," Felix replied, glancing at her. "I heard you blasted through several of the defensive gates using your Originium Arts. But if you keep overusing them like that, it'll damage your body."
W snorted twice, spitting to the side. "Hmph." She didn't bother to answer.
"I need to return to Babel," Felix suddenly said.
"What? We're on the verge of victory here—Kazdel's mobile city is about to fall! You're not staying to enjoy the glory? Why go back now?"
Already irritated, W's expression darkened. "Don't tell me you think Babel's people are pushing you aside? We're not that petty! You could take center stage at the victory banquet—let everyone know you were the one who split the gates open with a single strike!"
Felix blinked, then smiled faintly. He started to reach out — but instead of the gesture she expected, he merely patted W's shoulder.
"Thanks, W. It means a lot that you're angry on my behalf. But this isn't about recognition or glory. …Sorry, I have to go."
He'd seen them — hundreds of dark figures closing in on the Rhodes Island.
Glancing back at Kal'tsit, who stood calmly orchestrating the final assault, he met ACE's eyes and gave a small nod.
"Tch… what the hell is going on?"
W stomped her foot in frustration, watching as Hoederer, Ines, and even ACE followed after Felix. Their faces were grim — too grim for victory.
Why were they leaving the battlefield now?
Was this some kind of secret mission?
"Damn it," she muttered, breaking into a run.
---
A slender hand hovered over the control interface.
[Confirm shutdown of all-ship defense systems?]
From the earpiece came a voice — trembling, breaking, barely holding back tears.
The finger quivered once, then pressed down.