Disclaimer: All recognizable characters and themes are the property of Rick Riordan from the world of Percy Jackson and the Olympians. I am not making any money from this work of fiction. I'm just playing around in his sandbox.

A/N: Welcome to the sequel of Shelter. It has finally begun! If you haven't read the first half of this series, you may want to. I am planning to write it so that it can stand on its own, though you may miss references to events that take place in Shelter, and the Shelterverse one-shots: Atonement, Devotion, and Fulfillment.

It is my goal to write and post as I finish the chapters as I did with Shelter, so your feedback will be taken into consideration if you choose to leave any. Let me know what parts of the story strike a chord with you, what makes you feel iffy, what you hope to see happen, etc... I love to have a back and forth conversation with readers and Apollo is my muse. He likes to hover behind my shoulder and whisper what happens next into my ear as I type, and has also been known to talk to readers in the comments when he can't keep quiet about something.

Rated mature for future content. There will be smut, though I will warn in the chapters where it occurs.

Fasten your seat belts, folks, this is gonna be epic!

XxxX

The Stirring

Dirt trickles from the cavernous roof above, short streams of it followed by the eerie creaking of the structural supports settling. The dim glow of the green flame torches set into the walls doesn't make seeing through the dirty fog rising from the floor any easier.

Hades glares at the ceiling from his throne of bones, tapping his long white fingers on the end of the armrest, and then at the doors opening before him, displacing more dust. He narrows his eyes, cold and dark as tunnels as his refugee nephew flutters into the throne room, sending the clouds of dust newly wafting with his dratted winged sandals and hat.

"Lord Hades," Hermes says, touching down at last. "I have news."

Hades slouches in his throne, forcing himself to appear to be absently stroking his beard, rather than yanking on it with the frustration building inside him. "What is happening?" he spits, clipping his syllables.

Hermes wipes his brow, leaving a dirty smudge in the streaked sweat. He masters his face. The news cannot be good for Hermes to appear so serious. "Dedalus reports structural failures in the overpasses in Asphodel. He insists it isn't the materials, but the ground itself. The souls don't appear to realize anything is amiss, and he's having the time of it shuffling them through to prevent traffic jams. The processing for new arrivals is backed up the bank of the Styx …

"My lord," a new voice calls from the open doorway, carrying deep and low across the dark expanse of the bronze floor.

"What is it, Minos?" Hades demands, voice sharp as diamonds.

"We have a problem, my lord. The pavilion of judgement still stands, though the pillars are showing strain as if they're being forced upward. I do not know how long it will be before the roof gives way…"

"And?" Hades taps his fingertips once more upon his armrest. "The fields of punishment?"

Minos clears his translucent throat with a sound like churning gravel. "I am not positive. As the situation stands, none of the guards I have sent to check their status have returned. The fields nearest the castle appear to be intact, but the pit …We do not know how it is faring."

Hades flares his nostrils, pounding his fist. "Where is that insufferable janitor? Bob! Iaptus?" His voice rumbles through the throne room, sending more streams of dirt cascading from above.

A vibrating sound interrupts the silence that follows and Hermes pulls his cell phone out of his pocket. He pushes a button and holds it to his ear for a couple of seconds, then turns it off again with a weary sigh. "Lord Hades."

Hades tightens his lips, one black eyebrow twitching, and dismisses Minos with a long pointed finger. When they are alone again, save for the pair of skeleton warriors at the doors, he hisses. "What is it now?"

"It's bad. Asclepius, you instructed him to carry a message to Apollo through the dreams of his son, he was intercepted by, er … the man upstairs. Asclepius is in Tartarus. He was instructed to use his last phone call to send us a message. Monster activity in the world above has slowed to a crawl; the heroes have little to fight as the lord of the skies has commanded, and…" He takes a deep breath and releases it before continuing. "…and if either of us put a toe outside your kingdom, we are also to be cast into the pit."

Jets of blue-black flame shoot from Hades's eyes, incinerating an altar made from human skulls until only ashes remain. "How dare he–"

The air shimmers above the small golden throne beside Hades as Persephone materializes. "My lord," she says, bringing with her a breath of fresh air. She gives the throne room a cursory look, frowning. "I was expecting a little more pomp to celebrate my arrival."

Hades closes his eyes, reining in his anger. He opens them again and turns to face her. "Why have you come so early, love? It is not yet time for your descent."

She wrinkles her forehead and looks the Lord of the Dead over as if checking his sanity. "But it is. It's the 23rd of September and I am right on time."

Hades looks to Hermes, a sharp eyebrow raised.

Hermes lifts his cell phone and the antennae extends. "Martha. How long have we been down here?"

"Ohhhh, my head spinssss. Must you leave the vibration mode on all the time?"

"Be quiet, George. Hermes needsss us. We've been underground for two years. It's nearly October again."

"Isss it? I think it tastes more like November."

Hermes shuts off the phone and stashes it in his pocket. He gives Hades an apologetic glance. "They're not used to being cooped up in my pocket," he explains. "But time. And all the shifting…" He doesn't complete his sentence.

"It may be as I fear," Hades says, his voice reverberating off the walls.

"What is it?" Persephone asks, trepidation lacing her words.

"The remnants of Kronos have been consumed by Chaos, sucked into the vacuum and with him time. Time is spinning out of order." He closes his eyes, stretching out his power so a shiver races through the very walls. "I sense a force putting up resistance, but it's weakening. I must divert all my power to assist, though it will only prolong the inevitable."

"S-sucked into Chaos?" Hermes stammers, blinking as if he can't quite grasp the concept.

"But that means…" Persephone starts, and leaves off, gazing at the roof of the cavern with eyes wide with fear.

"Yes," Hades says, opening his eyes again. They stand out against his pale skin like icy shards of obsidian. "My baby brother is an idiot. Tartarus stirs.

XxxX

Nico wakes with a start, a sheen of cold sweat bathing him, the sheet clinging to his body. He lifts a hand to his face and scrubs the sleep from his eyes, his heart pounding against his ribs. His father is in trouble. He should be there helping him any way he can. Heart sinking, he sits up and peels the sheet from his chest, grimacing at how gross he feels. Will isn't going to like it. He climbs out of bed, pulling the bedding off along with him and tossing it in the corner for washing, then goes to the bathroom.

After a piss and a shower, he's starting to feel vaguely human again. He studies his reflection in the mirror, eyes blinking. The face looking back at him – it's him, but changed somehow, not quite what he expected. He opens the medicine cabinet and takes out his shaving cream and razor, his mind catching up with itself. Downloading missing data. As he scrapes the stubble from his face, he wonders where in Hades that idea came from. When he finishes, he looks at his face again, noticing the differences. He's not nearly as gaunt as he had been, the lost look in his eyes gone. The remnants of Kronos have been consumed by Chaos, sucked into the vacuum and with him time.

Nico shivers, trying to shrug off the vestiges of his nightmare. It clings to him like a cobweb, sticky and hard to displace. Two years, he thinks. Has it really been two years since Hermes and Asclepius had gone underground. Had he known them going underground had literally meant underground? No. He shakes his head at his reflection. This is news to him. Maybe Will knows something about it.

He returns to the spacious cabin and opens the curtain, squinting as the morning sun shines directly into his eyes. Will's probably either having his morning jog or practicing his archery from Apollo's chariot. The sunbeam grows at the thought, flooding his face with heat. "You asshole," Nico says aloud. He closes the curtains again. That's that question answered.

As he pulls on his clothes and straps his swords to his belt, the sense that something is just not right prods his brain as if starting a migraine at the base of his skull. Tartarus is stirring? What does that even mean? The monsters within the pit are building their forces, preparing to attack the upper worlds or worse – Tartarus, the primordial being is stirring?

He shakes his head again, attempting to dislodge the growing suspicion. There's no sense in panicking, at least, not yet. There has to be a bigger picture, a way to put it into perspective.