The deeper Nico and Will went into the Underworld, the quieter it became.

Not peaceful—never that. The silence here felt heavy, layered with distant echoes that didn’t belong to the living. The ground beneath their feet was dark and uneven, the air cold and stale, carrying the faint scent of stone, ash, and something older.

Nico walked a few steps ahead, shadows pooling around his boots like loyal guides. He knew this place better than almost anyone alive. The paths twisted, the caverns shifted, and the dead moved in slow, endless currents through the gloom—but Nico could feel the direction of Tartarus the way others felt gravity.

Behind him, Will Solace stumbled.

Nico caught the movement instantly and turned, reaching for him.

“Careful,” Nico murmured, steadying him by the arm.

Will tried to wave it off with a tired grin, but his face had already gone pale beneath the dim glow of Nico’s shadow-light. Being in the Underworld was wrong for him. Will was sunlight, warmth, breath. Down here, the darkness pressed against him like something alive, draining the brightness from his skin and the strength from his limbs.

“I’m good,” Will said, though his voice came out rougher than usual.

Nico didn’t believe him for a second.

“You’re leaning,” Nico pointed out quietly.

“I am not—”

“You’re leaning on me.”

Will paused, glanced down, and realized Nico was right. He was practically draped over Nico’s shoulder.

“…okay, maybe a little.”

Nico sighed but didn’t move away. Instead, he adjusted his grip, letting Will lean more comfortably against him as they kept walking.

“Almost there,” Nico said, though the words felt heavy in his mouth.

Tartarus was close now. He could feel it in the ground beneath his feet, like a slow, monstrous heartbeat buried deep below the earth.

And the voices—the ones that had haunted his dreams—felt louder here.

They had drawn him all this way.

Ahead of them, the cavern widened slightly. Jagged stone columns stretched upward into darkness, and a narrow path cut forward between them.

Nico stepped toward it—

And slammed face-first into nothing.

He staggered backward with a startled grunt.

“What—?” Will blinked, pushing himself upright.

Nico rubbed his forehead, scowling at the empty air in front of him.

“There’s… something here.”

Will frowned and reached out cautiously. His fingers brushed the same invisible barrier, stopping abruptly like they’d hit solid glass.

“Well,” Will said weakly, “that’s inconvenient.”

Nico’s jaw tightened. They had come too far for this.

He stepped back and tried again, pushing harder this time. The unseen wall held firm.

“Move,” Nico muttered under his breath, pressing both hands against it.

Nothing.

He tried shadow-traveling through it—letting the darkness gather around him—but the magic snapped back painfully, like the path itself refused to open.

Frustration flared hot in his chest.

“Seriously?” Nico snapped, slamming his palm against the barrier.

Will placed a gentle hand on his arm. “Hey. Maybe it’s a ward. Or—”

“I know what a ward feels like,” Nico said sharply, then immediately regretted the bite in his voice.

Will didn’t take offense. He rarely did.

Instead, he leaned closer to the invisible wall, squinting at the darkness. “Well, whatever it is, it’s not letting us through.”

Nico stepped back, breathing hard, exhaustion and irritation mixing dangerously with the dread already building in his chest.

They were supposed to reach Tartarus.

The voices had been pulling him there for weeks.

And now—

A deep voice echoed behind them.

“I believe that is the point.”

Both boys froze.

Nico turned slowly.

Standing in the shadow of a towering obsidian pillar was a figure Nico recognized instantly—tall, regal, draped in dark robes that seemed to swallow the dim light of the Underworld itself.

Hades.

The god stepped forward, his presence filling the cavern like the weight of a mountain. The air grew colder with every step.