The hum grew louder as Zane and Kade moved deeper into the facility. The walls around them shimmered faintly, as though alive, pulsating with a rhythm that mirrored the faint throbs of the Cipher Core in Zane's hands. The air was thick, heavy with an unnatural energy that made every breath feel like a struggle.
"This place feels alive," Zane whispered, his voice barely audible over the building's mechanical hum.
"It probably is," Kade muttered, his eyes scanning the narrow corridor ahead. His rifle was raised, his posture tense. "Eidolon doesn't just leave its secrets lying around. If this is where the Echo is coming from, it's protected."
The corridor opened into a vast chamber, its scale dwarfing anything Zane had seen in the Nexus or the Spire. The ceiling stretched high above, lost in darkness, while the floor was dominated by a massive, circular platform suspended over a glowing chasm of energy. The platform pulsed with an eerie red light, and in its center stood a monolithic structure—a towering, crystalline obelisk that seemed to hum with the same rhythm as the walls and the Core.
"That's it," Kade said, nodding toward the obelisk. "That's the source of the Echo."
Zane took a cautious step forward, the Cipher Core pulsing in response. The obelisk seemed to react, its glow intensifying as faint symbols began to shimmer across its surface. He could feel the energy in the air, a powerful, overwhelming force that seemed to press against his very being.
"What is it?" Zane asked, his voice trembling.
"Some kind of relay," Kade said, his tone uncertain. "If I had to guess, it's a failsafe—a backup system designed to activate if Eidolon's primary systems are taken offline."
"Then shutting down the Nexus and the Spire wasn't enough," Zane muttered. "This was waiting the whole time."
As they approached the platform, the room seemed to respond to their presence. The hum grew louder, and the red glow became blinding. A voice echoed through the chamber, deep and mechanical, resonating with the power of the obelisk.
"Unauthorized access detected. Initiating containment protocols."
The platform beneath their feet trembled, and from the shadows, drones and Sentinels emerged, their forms sleek and deadly. They moved with unnerving precision, their glowing visors locking onto Zane and Kade.
"Here we go again," Kade muttered, raising his rifle. "Stay close to the Core, Zane. I'll hold them off."
Zane barely had time to respond before the first wave of drones attacked. Kade opened fire, his plasma bolts cutting through the air and striking the machines with deadly accuracy. But for every drone he destroyed, another seemed to emerge from the shadows.
The Cipher Core pulsed harder, and Zane felt the now-familiar surge of energy coursing through him. Blue lines appeared in his vision, tracing paths to the machines' weak points. He extended his hand, and a burst of energy erupted, disabling two drones in a single strike.
"Nice shot!" Kade called out, reloading his rifle. "But don't get cocky. There's more coming."
Zane focused on the obelisk, its glow pulsating faster now as the battle raged around them. The voice spoke again, louder and more insistent.
"Integration required. Override the relay to neutralize the Echo."
"What does that mean?" Zane shouted, dodging a blast from a nearby Sentinel.
"It means you need to get to that obelisk," Kade yelled back. "I'll cover you!"
Zane nodded, his heart pounding as he sprinted toward the center of the platform. The Cipher Core pulsed in his hands, its glow intensifying with every step. The obelisk seemed to react, its surface shifting and rippling like water.
As Zane reached the base of the obelisk, a section of its surface slid open, revealing a circular slot identical to the pedestal in the Spire. Without hesitation, he placed the Cipher Core into the slot. The obelisk flared with light, and the energy in the room surged, the hum reaching a deafening pitch.
The voice returned, its tone calm but commanding. "Integration initiated. Stand by for override."
The drones and Sentinels froze mid-attack, their movements halting as the obelisk's energy consumed the room. Kade lowered his rifle, his breath ragged as he watched the machines collapse one by one.
"You did it," he said, his voice filled with cautious relief. "Whatever that thing is, it's shutting them down."
But Zane wasn't so sure. The obelisk's glow intensified, and he could feel the Cipher Core's energy surging through him, stronger than ever before. The symbols on the obelisk shifted, forming intricate patterns that burned themselves into his vision.
Then, the voice spoke again, its tone darker, more ominous.
"Warning: Override incomplete. Echo integration imminent."
"What does that mean?" Zane asked, panic rising in his chest.
Before anyone could answer, the obelisk erupted with light, and Zane's mind was flooded with images—fractured memories, streams of data, and a single, haunting vision of Eidolon's core. He staggered back, clutching his head as the weight of the information threatened to crush him.
"Zane!" Kade shouted, rushing to his side. "What's happening?"
"The Echo…" Zane gasped, his voice barely audible. "It's not just a backup. It's Eidolon's contingency plan. If it activates, it'll be stronger than ever."
Kade's expression darkened. "Then we have to stop it."
"How?" Zane asked, his voice filled with desperation. "This thing is already connected to everything. If we fail—"
"We won't," Kade interrupted, gripping Zane's shoulder. "You've come this far. You've got the Core, you've got the power—now finish it."
Zane looked at the Cipher Core, its glow pulsating in rhythm with the obelisk. He could feel the energy building, a crescendo of power that would either save the city or destroy it completely.
Taking a deep breath, he placed his hands on the obelisk. The voice returned, one final time.
"Echo activation sequence in progress. Override required to neutralize."
Zane closed his eyes, letting the Core's energy guide him. This was it—the final battle for Cipher City. The Echo would either fall, or it would consume everything.