Nico tugged shoved his hands in the pockets of James' old aviator jacket. The coat was too big for him but it was comfortable and smelled like their apartment. It was one of the only two things he had taken with him; the other being the leather notebook Chiron had given him two years prior. The book sat in the inside pocket of the jacket, heavy against Nico's chest.

He had only been on his own for a day and already he was beginning to wish he had planned before making his exit. He already knew that he wouldn't be able to keep up with the number of monsters he attracted by himself. When James had picked him up in February, Nico had already been exhausted from defending himself against monster after monster. Chiron's lessons and Emilie's writing warned him that they would come in droves now that he was stronger and it would be only a matter of time before he was overwhelmed.

He had to find somewhere safe. Somewhere he could hide from Camp Half-Blood, the Olympians, and the monsters that would inevitably hunt him down. But having left so abruptly he didn't have anywhere safe to lay low and catch is breath between battles. Without James or Chiron, Nico had only one alternative left to him.

He would go to his father, show him just how much he had learned, and ask for his help and protection. If anyone could help him reunite with Bianca, it was Hades.

Nico spent his first night on his own on the fire escape halfway up James' building and began his hike at first light.

The myths told of two main entrances to the Underworld: Charon's ferry and the hidden entrance Orpheus had used to rescue Eurydice. Emilie's writing told him the location of the latter.

He made it to Central Park by mid-morning. It was not especially busy with only a few couples and small families out in the grey spring morning. Nico's walk through the park took half an hour to find the spot described in Emilie's journal.

It was a cluster of large boulders heaped on top of each other in a haphazard pile. Nico raised the notebook, opened to a yellowed page with a charcoal sketch. He compared the two with his head tilted. Surely he had found the right place.

Nico tucked the notebook back in his pocket and glanced around the park. It seemed quiet enough with no one in sight.

He took a deep breath, feeling only a little ridiculous.

"Ninna nanna, ninna oh," he sang. His voice was flat and raw, not the melodic singing voice Bianca had inherited from their mother.

"Questo bimbo a chi lo dò?
Se lo dò alla Befana,
Se lo tiene una settimana
Se lo dò all'uomo nero,
Se lo tiene un anno intero.
Ninna nanna, ninna oh,
Questo bimbo me lo terrò!" (1)

The rocks shook in their own miniature earthquake. The two largest boulders slid apart, grating against each other all the way, to open a narrow gap that Nico could squeeze through.

He glanced back over his shoulder for one last look at the dusky park and slipped through the gap.

As Nico cleared the boulders, they slammed back together. The cave beyond was pitch black without a single shred of light to meet Nico's eyes.

He reached out blindly with both hands, feeling for a wall. The rough stone they met was damp and cool to the touch. Nico felt his way around the cave with his hands out in front of him like a game of Blindman's Bluff. He slipped on the stone floor as he began to edge his way through the corridor. The cave seemed to go on forever. It sloped steeply downward, eventually turning into haphazard narrow steps, and Nico was forced to keep one hand outstretched to the cave wall to keep himself grounded.

He didn't know how long he had been walking but it felt like hours when, at the very end of the corridor, the space began to lighten. The walls gradually became drier and the ground less slick. Nico's pace quickened as he chased the light at the end of the tunnel. It reflected warm and orange on the jagged stone edges of the cave walls, inviting Nico to run toward it.

As he neared the end of the tunnel Nico caught his breath. He had made it. The mouth of the cave opened up at the base of a cliff on a plain of black volcanic sand littered with bones. To Nico's right, a river of filthy dark water gushed from the rocks and roared off in a cascade of rapids. The cavern ceiling loomed high over Nico's head in a parody of what might have been storm clouds. The stalactites were wickedly pointed and glowed a faint grey. To his left was a wall of black stone. The only break in the wall was a huge arch at which lines of the dead had congregated.

A familiar monster stood over the crowd, watching the spirits six gleaming black eyes. Cerberus. He was almost translucent which made him difficult to see and Nico thought that he would not have noticed the enormous dog if he was not expecting to see him there.

Nico set his sights on Cerberus and picked his way down the rocky beach.

Cerberus giant noses twitched as Nico neared and the beast stood up to stiff attention. His three heads tilted comically with their foreheads creased in intense concentration. Friend or foe, he seemed to be wondering.

Nico whistled, high and clear, and Cerberus' ears perked forward. Three pink, slobbering tongues lolled out of his mouths. His stubby tail wagged wildly. Friend, he had apparently decided.

Cerberus bounded over the lines of the waiting dead to Nico. He stuck his noses down to sniff Nico all over, leaving his playful rump up in the air. Nico couldn't help but laugh as the dog investigated him.

"Hi, boy," he greeted fondly, giving a hearty rub to each of the dog's snouts. "Will you let me through the gate, huh, Cerberus? I need to go see Papa."

Cerberus let out a happy bark that made Nico laugh all over again. He jogged a few steps toward the line of waiting dead and Cerberus leapt after him, tail wagging furiously. The dog skidded back into position on his massive paws leaving giant skid marks in the ashy dirt.

"Stay," Nico ordered him.

Nico continued on his path by walking between Cerberus' front paws and underneath his furry belly to slip through the gates and past the security ghouls with the rest of the spirits. The guards eyed him curiously but Hades' edict from all those years ago rang true and no one made a step to stop Nico on his journey.

On the other side of the great walls, the entirety of Hades' kingdom was laid out around him. Nico had emerged in what must be the Fields of Asphodel. The black grass was a brittle, rotten, and over-trodden by the thousands upon thousands of undead. The field was dotted with clumps of poplar trees and fallen stalactites.

The faces of the dead were difficult even for Nico to focus on. Their expressions shimmered making them look constantly angry or confused. They approached him, attempting to speak but their voices came out like the nonsense chatter of bats twittering. When they realized Nico couldn't understand them, they moved on looking even more crestfallen.

The line of the newly deceased wound through the field to a black-tented pavilion where a banner proclaimed: JUDGMENTS FOR ELYSIUM AND ETERNAL DAMNATION. Two much smaller lines snaked out the back of the tent.

To the left, security ghouls marched spirits down a rocky path to the Fields of Punishment. It was a vast wasteland sectioned into different torture areas by minefields, fences of barbed wire, and rivers of lava. A warm, moist wind blew a strong scent of sulphur up from the glowing and smoking fields.

The line coming from the right side of the judgment pavilion was much shorter. It led down a gentle hill to a small valley surrounded by delicate bronze walls. Elysium was full of beautiful houses from every time period in history, from Roman villas and medieval castles to Georgian mansions. Silver and gold flowers bloomed on the lawns and the grass rippled in a rainbow of colours.

A shimmering blue lake lay in the centre of the valley, dotted with three small islands. Nico knew that they must be the Isles of the Blest where those who had chosen to be reborn three times and had three times achieved Elysium.

Far away in the gloom, Hades' palace stood tall with black stone walls and bronze gates. The ramparts were alight with fire. The palace glittered with black obsidian and shining bronze.

It got darker as Nico left the judgement pavilion and moved deeper into the Asphodel Fields. He could see the colour fading from his clothes and his skin became a washed out pale. As he neared the gates of Hades' palace the crowds of spirts began to thin.

A pair of skeletal guards stood at attention on either side of the main gates. This time, the gates were opened for him with ease and he was gestured into Persephone's garden.

He remembered the garden very well; the flowerbeds overflowing with golden plants and gemstones, and the skeletal white trees sprouting from marble basins. Iron steps led up to a large, semi-circular veranda where a pair of thrones, one bone and one silver, sat with a view of the Fields of Asphodel.

A woman was waiting for him seated on the silver throne. Dark hair cascaded down her back in a tumble of curls. Her skin was darker that Nico's own olive, but was washed out pale like she hadn't seen the sun in far too long. Her eyes were the same way, multicoloured but faded as if the Underworld had sapped her life force.

He had a feeling that in the world above she would be beautiful, even brilliant. Even her dress shimmered with beauty, flowers blooming throughout the fabric, constantly shifting and changing as she moved. Nico swallowed hard when he saw the expression on her face. Her lips curled into a sneer, her eyes burning with anger.

When he saw that look, Nico immediately knew who she was. She was his father's wife, Nico's stepmother, Persephone, Queen of the Underworld.

"And just what," she demanded, "are you doing here?"

Nico's heart stuttered. This was anything but good. He supposed he shouldn't have expected anything different; his last experience in the underworld hadn't exactly gone swimmingly and so far this visit had been far too easy.

"I–" He cleared his throat. "I came to speak to my father."

"Lord Hades is an exceedingly busy god, boy. Your business can wait."

"Please," Nico insisted. "I need to see him. It's important."

The air above the obsidian throne shimmered and Hades appeared seated regally as ever beside his wife. He smoothed some invisible crease from his black robes and looked down his long nose to Nico. His robes made him look rather like the l'uomo nero (2) from the ninna nanna (3) he had sung to gain entry to the Underworld.

"Nico," he said, in lieu of a greeting. "I thought I sensed your presence."

Persephone huffed and looked away, resting her head on her fist as she leaned against the arm of her throne.

Nico bowed, just because it seemed like the thing to do. He felt very small standing in the garden beneath the balcony with the gods looking down on him.

"Well? Why exactly are you here?"

Nico's mouth was dry. "I came to ask–"

Nico cursed himself. Despite the years since his last meeting with his father, he apparently had not developed a backbone. There was something about Hades that sent all the wits and composure Nico ordinarily clung to out the window.

It must be his aura, he decided. Just as Hestia had instilled a sense of warmth and belonging when they had met that first day at Camp Half-Blood, Hades gave him a feeling of unease that threw him entirely off balance, as if anything he said or did would only condemn him in his father's eyes.

"Yes?" Persephone snapped. "Spit it out."

"For protection."

"Protection," Hades repeated.

"Yes," said Nico. "I don't have anywhere else to go. Now that Camp Half-Blood expelled me there's nowhere safe for me."

"And you expect me to take you in." It wasn't a question.

Now that he heard it out loud, Nico realized how ridiculous the idea was. Hades, the God of the Underworld, Lord of the Dead, providing shelter to a lone demigod? It was absurd. He had been foolish. Nico looked down, he should have known better.

"Well… yes. But I was also hoping–"

Persephone let out a sharp, forced laugh. "A half-blood? Live in the Underworld?"

"Persephone, my dear," said Hades, holding up a hand for silence.

Persephone cut her eyes at Hades and raised her chin stubbornly. "Don't you 'my dear' me, husband. You cannot seriously be considering this, allowing one of your bastards into my house?" She folded her arms and gave her husband a pointed look, daring him to argue.

"Nico is my son," said Hades, in that irritatingly placating way. "I will not allow Zeus to take another one of mine. When Maria–"

"Do not bring her into this," Persephone snapped, slamming her palms down on the arms of her throne. "If you insist on upholding this damned sham of a marriage, you will do me the courtesy of keeping that harlot's name out of this palace."

That loosened Nico's tongue. "Don't talk about my mother like that!"

Persephone's eyes flashed with anger. "I beg your pardon?" she hissed. "What did you say to me?"

Nico's eyes darted to his father, but Hades had his eyes half-closed and two fingers to his temple as if fighting a migraine.

"I won't let you talk about my mother like that," Nico repeated. A growing sense of dread pooled in the pit of his stomach even as he spoke.

Persephone's eyes narrowed. She raised a hand, her fingers sparkling rosy pink with energy. Nico squeezed his eyes shut, waiting for the blast.

But it never came.

He opened his eyes.

Hades held Persephone's wrist in his pale, spider-like fingers. She held her husband's gaze, her eyes fiery in the shadowed room. Nico watched as Hades' grip loosened and lowered his wife's hand.

"Enough, Persephone," he said slowly. "He is only a foolish boy, his words mean nothing. We can put this situation to our advantage." Persephone let out an angry huff and tore her arm from her husband's grasp. "He will bring greatness to this realm, my dove," Hades insisted, "the Hero of the Prophecy. And when he saves Olympus we will be honoured above all other gods."

Nico's stomach flopped. 'Saves Olympus'? Chiron had told him what the prophecy would entail, but hearing that expectation from his father set his nerves jangling all over again. From what he had heard, prophecies were more likely to get him killed than anything else. After the war, Chiron had even urged the Oracle to give camp a wide berth to allow the campers a rest. Nico didn't want to be a part of some prophecy. He didn't want that burden. There had to be another way to earn his father's approval.

Persephone pursed her lips and lowered their hands, her posture still tense like a cat ready to spring. "Fine," she hissed, voice venomous. "Then I will not hear a word of the woman. And if he ever speaks to me like that again…" she let the threat hang in the air.

"Agreed."

Persephone shot Nico a withering glare and vanished in a whirl of flower petals.

"I would advise you to hold your tongue in future," Hades said calmly, turning to his son. "Persephone can be quite prideful."

"I noticed," Nico snapped. The trepidation he had felt since Hades appeared in the room was gone, replaced by sizzling anger. "How can you let her say things like that?"

Hades sighed and drummed his fingers on the arm of his throne. Evidently, he did not want to answer questions about his wife. "Nico, as much as I cared for your mother, Persephone and I have been bound for millennia. You are a mortal. You could never hope to understand the intricacies of the situation. Now enough of this. You came to ask for my protection. I am willing to grant you sanctuary here in my realm–" At least that's something "–but only under the condition that you continue your training. The agreement with Olympus stands that you will be granted immortality at the age of sixteen if you prove yourself worthy to take on the prophecy and the mantle of Champion of the Underworld. I intend for you to do so."

"I've already been trained," Nico said shortly. "Chiron taught me himself."

Hades snorted. "Two years under that old centaur's falling standards is hardly adequate. No, you will begin your training tomorrow."

Nico gritted his teeth and forced himself to take deep breaths. Speaking out on behalf of his mother had gotten him nowhere, and somehow he doubted his father would be receptive to a debate on Chiron's training schedule.

"Yes, father," he ground out.

Hades either didn't notice or didn't care that Nico was so unenthusiastic about the idea of further training. "Go on then," he ordered, gesturing to the doors of the palace.

"Wait."

Hades arched an eyebrow at him.

"Please," Nico amended. "I– I had a favour to ask."

"You have already asked for quite a large boon," Hades sounded amused, "but ask."

"I want to see Bianca."

"Your sister is with the Artemis' band of Huntresses," said Hades. "I have no control over her movements." Nico opened his mouth to respond but Hades cut him off. "I will consider your request and speak to my niece. Now go, Alecto will meet you."

The doors swung open without Hades so much as lifting a hand. Nico bowed again and made his way to the doors. When he reached them, he glanced back over his shoulder, and Hades was gone, leaving nothing but an empty throne behind him.

As soon as he left the garden, Alecto seized him from the entryway and hauled him down to the basement levels at the back of the palace. Nico shrugged his shoulder, attempting to push the clawed hand off. The grip was tight and uncomfortable, the sharpened tips of Alecto's talons caught at his shirt.

It was damp, dark, and freezing at the bottom of the castle. The heat from the braziers seemed to stop just short of warming Nico's skin and he shivered against the cold. A narrow door stood at the end of the corridor, a heavy iron lock set into the wood. Alecto inserted a claw into the lock and twisted. Nico heard the telltale click of it unlocking and privately thought that it seemed an inconvenient way to pick a lock. The door swung open.

Inside was a cluttered workshop, full of jumbled artist's easels with hand-drawn sketches and diagrams of buildings and contraptions Nico had never seen before. Glass jars of green oil lined one shelf and strange metal machines that Nico couldn't make sense of were crowded into the corners of the room.

In the midst of it all stood a fit-looking man in his fifties. He bent over a table strewn with schematics and diagrams Nico didn't understand. He looked up at their entrance and gave a dry sort of smile. He wore his grey hair short and had a neatly clipped grey beard. Under a worn leather apron, he wore navy pleated trousers with a plain bush shirt. At the base of his neck was a strange mark, a purplish blotch like a birthmark or a tattoo, but before Nico could make out what it was he shifted his shirt collar. The mark disappeared under his clothes.

"Why, Alecto," he said. "You haven't brought guests to my humble shop in centuries. Had l known, l would have tidied up."

Alecto did not seem as pleased to see him. "This is Nico di Angelo," she rasped. "He will stay here in the palace in your charge."

The man coughed awkwardly. "I don't believe that is part of my agreement–"

"The Lord's orders!" Alecto interrupted, shoving Nico forward into the shop. "See to it that the boy is kept busy."

"But–"

Alecto had already disappeared in a flap of leathery wings.

The man sighed heavily. "So, Lord Hades has put you with me, hm?"

Nico looked up at him through his fringe, it had been a while since anyone had taken him to a barber. "Yes, father said you were going to train me."

The man blinked. "Son of Hades, eh? Well, who are we to argue?" Nico huffed, blowing at his fringe. No one, Hades had made that quite clear. Hades had a plan in mind and Nico was in no place to argue. "Quintus," said the man, offering Nico his hand to shake, "I serve Lord Hades redesigning and repairing the Underworld. Explore a bit, I need a moment to organize my plans and then we will see about finding you a place to sleep."

As Quintus shuffled with his various papers and plans, Nico wandered around the workroom. Upon closer inspection, he could see just how massive the room was. It almost rivalled the size of the sword arena at Camp Half-Blood. Strange contraptions hung from the ceiling, whirring and spinning seemingly pointlessly. Nico had never seen such inventions before. Several blackboards on wheels were scattered amongst the various inventions and covered with calculations so cramped Nico wondered at how anyone could make sense of it.

As he neared the back of the room, Nico's face broke into a grin. A wall of weapons, all in a shining bronze hung before him. Weapons were something he understood perfectly. They looked ancient, but none seemed to be falling into disrepair. The green torchlight bounced off of the metal, jumping out at his eyes. An enormous battle axe loomed menacingly above Nico and he quickly sidestepped away to the smaller blades.

A row of throwing knives was strapped to a leather belt, hung on display like trophies the way a hunter would present his guns, and above them an archer's bow and quiver. A sword hung above its sheath was centred in the display. Nico had never seen anything quite like it before. At Camp Half-Blood, all of the swords were celestial bronze but what the sword hung above him was black as night, its iron blade gleaming in the torchlight.

Nico dragged a stool over from an easel and climbed up. He stretched on the tips of his toes and reached out for the sword, fingers itching to grasp its hilt. Just as his fingertips brushed the leather he overbalanced, stumbling forward. His hand grabbed at the sword for balance, knocking it from its perch.

But there was no crash.

An unfamiliar but strong set of hands had caught Nico around the waist and the weapon by the pommel.

"Careful, boy." It was Quintus. He stood over Nico, not a trace of anger in his stance. "You'll hurt yourself, straying into things that you shouldn't." He offered Nico a good-natured smile and replaced the sword on the wall. "Now come, let's get you settled."

They traipsed back upstairs out of the basement levels and Quintus steered Nico with a hand on his shoulder to the third floor of the palace. Despite a rather significant lack of living beings to occupy them, Hades' palace was equipped with dozens of bedrooms.

Nico would apparently be taking up residence in the east wing, on the opposite side of the palace from his father and Persephone. He didn't know if that was some sort of protocol, the King and Queen of the Underworld having a wing to themselves, or if Hades or Persephone had arranged for Nico to be kept as far from their sight as possible.

Nico's bedroom was huge. He had expected something similar to the guest room at the Big House, small, and soft, and warm, and homey, and nothing like what lay before him.

The floor was black granite without so much as a rug to add even a hint of softness. The curtains over the window were black velvet, and long enough to just brush the stone floor. A narrow door led out to a small balcony overlooking Persephone's garden, with a view stretching passed the Fields of Asphodel to the River Styx. A four-poster bed with black silk bedding and silver trimmings housed a veritable mountain of pillows that dominated the headboard, practically begging Nico to collapse into them. On either side of the bed was a table set with an oil lamp.

An enormous fireplace was set into the wall directly opposite the bed, empty and cold. A stately looking desk stood to the right of the door, bare but for a table lamp and a small pile of blank pieces of parchment. A tall wooden dresser stood on the other side of the door and a large trunk sat at the foot of the bed. Deep purple wall hangings with silver embroidery draped down the stone in a likely attempt to make the room warmer and more comfortable.

Flaming torches hung from the walls lit with green fire. A chandelier of interlocking bones was suspended from the ceiling, carrying iron brackets with candles alight with green flame. One wall housed a second door that, upon inspection, Nico found to lead to his own private bath. The other held a set of stately, windowed, double doors that opened out onto a small balcony with wrought iron railings.

"This should do," said Quintus, passing his gaze over the contents of the room. "There are very few in residence at the palace so this wing is not normally in use."

"This is all mine?" Nico asked.

"All yours," Quintus agreed.

Nico grinned. He hopped up to sit on the bed, bouncing a little on the soft mattress.

He cocked his head at the torches on the wall. "Why is the fire green?"

"Ah," Quintus smiled, "that is Greek Fire, lad, burns as long as there is fuel and is unquenchable by water. It is a necessity in the Underworld to keep the fires burning. Now, while you are in my care I would ask that you do not venture out of the palace grounds without supervision. The staff will be informed of your presence but I do not think that a run in with your father's guards outside of the castle grounds would be a good idea."

Nico didn't particularly mind that edict. 'Don't wander off' was a simple rule that had been true everywhere Nico had lived and he suspected he would find equally simple ways around it.

"Get some sleep," Quintus urged him. "We will begin your training tomorrow."

Translations:

1. An Italian lullaby, Ninna, Nanna. Translates to:

Lullaby, lullaby, ooh,
Who will I give this baby to?
If I give him to the old hag,
For a week she will keep him, ahh.
If I give him to the bogeyman,
For a whole year he'll keep him,
Lullaby, lullaby, eeee
I will keep this baby for me!

2. "l'uomo nero" literally translates to "the black man" but it should be noted that in the context of this lullaby there is not a racist connotation. It refers to a man dressed all in black who was used as a warning to Italian children to listen to their parents. The Bogeyman.

3. "Ninna Nanna" means lullaby.