The air thinned the moment Nico opened the passage.

Shadows folded inward like curtains being drawn, the familiar cold settling into his bones as the world above peeled away. The Underworld greeted them with its usual silence—heavy, ancient, expectant. Ash-gray stone stretched in every direction, broken only by the distant glow of rivers that were not meant to reflect light. Will’s hand tightened around Nico’s automatically, fingers warm and grounding even as the chill crept up his arms.

“You okay?” Will asked quietly, his voice steady but alert, the way it always got when he slipped into healer mode.

Nico nodded, though the movement cost him more than he liked. “Just… keep close.”

The quest hadn’t gone how it was supposed to. They’d been sent to retrieve something small—important, yes, but not worth the amount of resistance they’d met. Monsters had poured out of the shadows like the Underworld itself had decided to test them, and somewhere between fighting and fleeing, Nico had taken a hit meant for someone else. The wound wasn’t fatal, but shadow travel afterward had torn through what little strength he had left.

Now every step felt too heavy. Every breath scraped.

Will noticed anyway. He always did.

“You’re bleeding again,” Will murmured, glancing down at Nico’s side where dark stains spread through his clothes. His jaw tightened—not in panic, but in that focused, determined way Nico had come to trust. “We need shelter. Now.”

Nico swallowed, vision flickering at the edges. He could feel the Underworld pressing in, responding to him, recognizing him—but even that connection felt distant, frayed. Still, there was one place here that would answer. One place that was safe.

“I know where to go,” Nico said, voice low. “Follow me.”

They moved deeper, past jagged rock and whispering shades that bowed their heads as Nico passed. Will caught the way they stared—curious, wary, reverent—but he didn’t let go. He adjusted Nico’s arm over his shoulder instead, steadying him when his steps faltered.

The castle rose from the darkness like a memory made solid.

Black stone, impossibly tall, its towers cutting into the gloom. Pale green fire burned along the parapets, casting long shadows that stretched toward them like reaching hands. Will sucked in a breath—not in fear, exactly, but awe. This wasn’t like Olympus. This place didn’t shine. It endured.

Nico paused at the gates, breath shallow. The weight of the wound hit him all at once, knees threatening to buckle.

“Hey,” Will whispered, sliding fully in front of him now, hands gentle but firm on Nico’s shoulders. “Stay with me. You did great. I’ve got you.”

Before Nico could argue, the gates groaned open.

The temperature shifted instantly—still cold, but controlled. Intentional. Footsteps echoed across the stone hall as they were ushered inside by unseen forces, and then—

“Nico.”

The voice rolled through the chamber, deep and resonant, carrying the weight of centuries. Hades stood at the far end of the hall, dark robes flowing like living shadow, his expression sharp the moment his gaze landed on his son.

Nico straightened on instinct, pain flaring. “Hi, Dad.”

Hades was at his side in a heartbeat.

His eyes flicked over the wound, the exhaustion written into Nico’s posture, and something fierce and unmistakably protective crossed his features. “You are injured.”

“I noticed,” Nico muttered weakly.

Hades turned his attention to Will then, studying him openly—golden hair stark against the gloom, eyes bright even here. “And you must be the healer.”

Will swallowed, but didn’t back away. “Will Solace,” he said, offering a small nod. “Apollo’s son. Nico’s—” He hesitated only a fraction of a second. “Boyfriend.”

Something unreadable passed across Hades’s face.

Then, slowly, he inclined his head. “You brought him here when he needed sanctuary,” Hades said. “For that, you have my thanks.”

Will blinked, surprised, then nodded. “I’m just doing my job. And… I care about him.”

“You will rest,” Hades said firmly. “Both of you are under my protection while you remain here.”