Full Summary: (Set between Blood of Olympus and The Hidden Oracle, high probability of spoilers for both. Rated for language and violence.)

With Apollo missing in action, the Sun Chariot cannot be pulled across the sky; thus, the world is plunged into an eternal state of nighttime. His son, Will Solace, takes it upon himself to awaken Helios - the original god of the sun - and bring light back to the world. But first he has to figure out how to revive a god that has long since faded away, and he can't do it alone.

Nico di Angelo may be having frequent nightmares, but that doesn't stop him from joining Will on his mission (only to make sure the son of Apollo doesn't get himself killed, obviously, that's the only reason, he swears). But between said nightmares, a pair of jokester demigods who don't seem to be taking this seriously, and a shady and callous Hunter of Artemis along for the ride, Nico might've signed up for more than he bargained for. Did we mention that he's still banned from shadow travel and other assorted "Underworld-y powers"? Because Nico's still a little salty about that, especially considering his growing attraction to the boy who made that order in the first place...

"Get in the car, losers, we're going questing." - Nico, probably

A/N: So hey guys, bet y'all thought you'd seen the last of me. This is the first Actual Fanfic I've written in like six years so I'm suuuuuper rusty. Hopefully It won't reflect too much in my writing. Anyway, this fic is crossposted to my AO3 account (lunardance) with a few choice extras that I can't show here on . ;D

Hope you guys enjoy! Reviews and favs are loved!

A/N the Second, 5/6/16: Soooo after having read The Hidden Oracle, I've decided to retcon a couple of things to make this more canon-compliant. Nothing major; if you've read this before, you'll just notice a lack of a certain deity in this chapter. If you're here for the first time, then welcome!

Sol Invictus

After everything he'd been through, Nico had come to appreciate the sunlight a bit more.

There was no sunlight in the Underworld, or in the deepest depths of Tartarus. There was no sunlight in the bronze jar that Otis and Ephialtes had held him captive in. The sunlight had completely left his world the moment that Percy had told him what had happened to his sister.

However, now he readily accepted its presence, even reveled in it.

He sat there, atop the roof of his cabin - his new favorite place, he'd found, since beginning the renovation of Cabin 13. Nobody could find him up there, nobody could bother him. He was alone with his thoughts, alone with the mid-August sun bearing down on him.

The light washed over his body, warming him from head to toe; it cupped his face with the gentlest of touches. The crisp afternoon breeze combed through his thick hair like fingers, and for all intents and purposes, he should've felt calm, he should've felt safe.

But he didn't.

Nico knew it was going to happen, and it wasn't a matter of what, but when.

His palms were sweaty, his hair stood on end. He forced himself to keep his eyes focused on the sky, watching, waiting. It's bad for your eyesight, Jason had told him, everyone had been telling him that since the day he was born. But it wasn't enough to deter him - he had to see it with his own eyes.

Everything came crashing down.

This was what he'd been waiting for. He pushed himself up from his spot on the roof and bit back a scowl as the sun itself broke and crumbled, shattering into a million pieces like glass thrown to the floor. He stood his ground as the blazing shards fell from the sky, fell to all corners of the earth, fell toward him, burning holes in his clothes and embedding themselves in his skin.

There was no pain. With sunlight, there was never pain. It was what came afterward that made him cry out.

The sky darkened as the shards began to cool, growing darker and darker until there was but one tiny pinprick of light hanging where the sun used to be.

Nico's surroundings were pitch black. The splinters of light pulsed beneath his skin, illuminating his veins and syncing themselves with his rapidly quickening heartbeat. And around his legs, he could feel that familiar freezing haze creeping in.

He was sinking into the shadows again, as he was wont to do, but all he could feel now was sheer terror.

Help, he tried to call out. But, as always, his voice failed him as the tendrils of darkness enveloped him and crept down his throat.

Try as he might, there was no breaking his bonds. From the faint light of the shards beneath his skin, he could see his body literally being erased as he sank further into the black depths.

Give in, Nico, that voice spoke from inside his head, from all around him, from the very core of his being. The shadows are your friend, are they not? So cooperate with them.

Become one with them.

Become the shadows.

That tiny spot of light hanging in the blackness had begun to flicker. Nico could feel his pulse racing, throbbing in his head so hard that his vision went dark entirely. All that was left was that painful pounding, beating so loudly in his head that his consciousness finally wavered.

That was when he jolted awake.

Gasping for breath, he sat up in his bed and wrapped his arms around himself. "It's okay," he muttered quietly, "it was just a dream." That same one he'd been having all week, but a dream nonetheless.

Once his breathing got under control, he reached for the clock on the nearby nightstand. 12:38, it read. The room was still completely dark save for the faint green torches on the walls. Was it really only midnight? It felt like he'd been asleep for hours, and the nightmare hadn't wasted any time before kicking in.

Heaving a sigh, he rested his head in his hands. He could still hear his heartbeat pounding in his ears.

His heartbeat sure sounded a lot like a door.

Nico shook his head for a moment as he regained his bearings. Yeah, that was definitely the door.

"What in the world…" he growled under his breath as he got out of bed, pulling on the nearest pair of pants he could find. "I'm coming, hold your pegasi…" When he opened the door and met the sky-blue eyes of Will Solace, he was simultaneously surprised and not surprised at all. "Solace, are you out of your mind?" he snapped incredulously.

Will simply raised a hand in greeting. "Morning, Death Boy. Did I interrupt your beauty sleep?"

Nico buried his face in his palms. "Okay, for one, stop calling me that, and for two, it's half past midnight! What are you even thinking, I'm surprised that the harpies haven't eaten you a-"

Suddenly, what was happening behind Will registered in Nico's mind. "-live?"

The entire camp was bustling. Every single cabin was illuminated, yet it was still so dark outside that he could easily see the stars. But there was a lingering sense of tension in the air, he could tell that much from how frantically the other campers were addressing each other.

That feeling that Nico always got when something was very, very wrong bubbled up in the pit of his stomach. "...Will, what's going on?"

Will rubbed the back of his neck, a sheepish look on his face. "Yeeeeeeah, about that… Chiron's calling a counselor meeting. Thought you might want to be awake for it."

Nico blinked at him, still trying to process the information. After a moment, he sighed in defeat and rested his head against the door frame. "Yeah, okay. Just… give me a moment."

As the two of them walked toward the Big House, Nico couldn't keep himself from glancing around at all the ruckus. There was a large flock of campers surrounding the Athena cabin, as if that was where all of the answers were. Many were up at the dining pavilion, chowing down like it wasn't the middle of the night.

Nico resigned himself to the idea that he wouldn't get any answers until they all spoke with Chiron. He turned to Will, raising an eyebrow. "Did you seriously think that pounding out the Arceus theme against my door was the best way to wake me up?"

Will smirked over at him, not bothering to hold back his snort. "Oh my gods, you are such a nerd for recognizing that. I think you played a little too much Pokemon while you were stuck in the infirmary."

"Says the one who beat the song out on my door!"

"Dude, you were at the Elite Four by the end of the second day."

"You're the one who loaned me the game in the first place!"

"You asked if I still had it!"

Nico groaned, tossing his head back in frustration. "Look, Solace, just because you let me borrow it that one time when I was ten-"

"Man, you guys fight like an old married couple," Percy's voice interrupted.

Nico turned in the direction of the voice. There he was, Percy Jackson himself, propped up against the wall of the Big House. The door next to him was open, and from what Nico could tell, a lot of the other counselors had already gathered there. "Shut it, Jackson," Nico retorted, his ears burning.

Will simply cackled in response, punching the air in victory. "Solace 1, di Angelo 0," he laughed, before turning his attention toward the son of Poseidon. "'Sup, Percy? Everyone else there already?"

Percy nodded, motioning for them to follow him inside. "Yeah, we're all here, we've just been waiting for you kids to show up."

Nico crossed his arms in a huff as the three of them stepped inside. Sure enough, the other head counselors were present, as well as Chiron, who had a worried look in his eyes. At first, nothing seemed out of the ordinary: Clovis was naturally asleep, Nyssa was filling in for Leo - Nico felt a pang of sadness at the thought - and Jason and Piper were having an animated discussion about the former's traveling plans.

He didn't notice the stranger present until he took his seat at the table.

He recognized the girl as a Hunter of Artemis, leaned against the wall looking like she would rather be anywhere else at the moment. She twirled a strand of platinum blonde hair around her finger, her pale blue eyes focused rather intensely on the opposite wall. Nico couldn't help but frown at her presence - did that mean the other Hunters were here?

Judging from the amount of tension in the room, he had a feeling that some sort of crisis was happening. Again. It had barely been two weeks since Gaea's defeat. The camp really, really did not need another crisis right now, much less so soon after the last one.

Chiron's voice broke his thoughts. "Everyone here?" the centaur asked, scanning the room. "Let's begin, then."

"Alright," Clarisse spoke up, slamming her hands on the table. "Can someone please explain what in Hades is going on?"

"I don't think any of us really know, Clarisse," Annabeth replied, checking the time on her wristwatch. "It doesn't make any sense whatsoever - it's almost one and it's still dark outside."

Nico raised an eyebrow at the observation. "Why wouldn't it be," he asked, "it's one in the morning?"

"Uh… not exactly, Nico," Jason said, pushing his glasses up on his nose. "It's one in the afternoon."

Nico gave Jason a blank stare. He turned to look out a window, still seeing the night sky above, and then looked back to Jason. "What."

Annabeth groaned and rubbed at her temples. "Right now, the popular theory among my siblings is that because Apollo is technically AWOL now-"

"'Cause Zeus kind of vaporized him for no real reason after we defeated the giants," Percy cut in.

"-then there's nobody around to drive the sun chariot, so it's just… always night now. But that's not how it works, speaking from a scientific standpoint. The sun can't just stop rising like that, it'd throw literally everything off balance."

Nico could see Will tense up from the corner of his eye. He hadn't known what exactly had happened at the Acropolis, but from what he'd learned from the others, it didn't sound good. Zeus had, for some reason, pinned the entire blame on Apollo and decided that he should be punished for it.

He could sympathize with the blond, though. It really sucked not knowing where a parent had ended up.

"I don't think there's a scientific reason behind this," Will spoke up, his voice unusually somber.

Lou Ellen of Hecate cabin nodded from Will's other side. "Whatever it is, it's got the Mist working overtime," she replied, "I can feel how thick it is outside of the camp grounds. It's trying to cover something up, but whatever it is, it's so vast that it's having to work extra hard."

Clarisse growled and crossed her arms, sitting heavily in her seat. "So, what? That's it? Apollo's gone and that means no more sun? I can't believe this."

Chiron heaved a sigh and stroked his beard for a moment before gesturing to the pale Hunter leaning against the wall. "Lady Artemis has sent one of her Hunters along with a message. She may be able to shed some light on the situation."

Without a word, the Hunter nodded and reached into her silver jacket, pulling out a scroll. She moved toward the table and carefully unfurled the scroll before spreading it out over the table. The scroll started glowing with a faint silver light, and before long, a small holographic projection of Artemis herself stood over it.

"As many of you may know," she began, "my brother has been punished for his transgressions against our father Zeus. As of right now, our father is undecided on what said punishment will entail, so Apollo is currently in a state of divine limbo. Quarantined, if you will.

"Undoubtedly, you've noticed the effects that his absence has brought upon your world. There is no sun. My own moon has become shrouded with darkness. The stars are now solely responsible for providing light to your sky. Which is why I have decided to issue my own personal quest to any demigod who wishes to step forward to rectify the problem. My only requirement is that the messenger I have sent, Mena, accompany you on the quest.

"There is something very dark and very dangerous afoot. With my brother missing in action, dark forces are now able to rise from the pits of Tartarus and cast their shadows upon the world. There is no telling when Apollo will be allowed to rise again, so what I am proposing is a backup plan of sorts - to awaken our original solar deity, to bring his light back to the world until Apollo can be reinstated."

She said no more, and the hologram briefly flickered before disappearing entirely.

"Original solar god?" Piper asked, a confused look on her face. "Does she mean Helios?"

The name definitely rung a bell in Nico's head. "But he's faded, isn't he," he started, "him and Selene. Apollo told me that much when he brought me to camp, I remember he said that the Romans wanted to 'downsize'..."

"So, what does that mean for us?" Nyssa spoke up. "If a god has been allowed to fade, then there's no bringing them back, is there?"

"There may be," Chiron responded. "It is unknown if it will work for a god, but I recall a demigod once Googling the sisters of Medusa, allowing them to fade back into existence…"

Percy stood up, placing his palms flat on the table. "Yeah, yeah, I remember this!" He glanced around the room. "Annabeth, Nico, you remember, right? When we found Pan in the Labyrinth, and he said he should've been dead like two thousand years ago but 'cause all of the satyrs still believed in him, he wasn't able to fade."

Nico frowned at the mention of the Labyrinth. He definitely remembered the encounter with Pan, but the god had barely acknowledged his presence. "Yeah, I remember."

"I do too," Annabeth said with a nod. "Where are you going with this, Percy?"

The son of Poseidon fixed his eyes on Nico. "Apollo said that the Romans assigned the roles of Helios and Selene to him and Artemis, yeah?" Nico quietly nodded in confirmation, and Percy turned to Jason. "Jason, bro, you think that if we took this over to Jupiter like 'hey, y'all dropped the ball on the whole sun and moon god thing', then we might be able to like… make them fade back, or something?"

Jason looked thoughtful as he rubbed his chin. "Maybe not in so many words, bro, but it might be worth a shot. It's not that the Romans were lazy about Sol and Luna, though. They actually believed that there were two sun gods - Sol Indiges wasn't really important to to them, unfortunately, and he did end up fading. But then in the late Roman Empire, there were a lot of cults springing up around a second god, Sol Invictus." He shrugged and crossed his arms. "But it was different with Luna. She wasn't really regarded as a distinct goddess so much as an epithet of Diana or Juno."

"So eventually, they both faded out," Will mused, "but because these cults of Helios started showing up, then he kind of came back?"

Jason shrugged again and pulled his glasses off, cleaning the lenses with his shirt. "I guess so. The later Roman emperors really favored Sol Invictus too, if that helps anything."

"So it stands to reason that if enough people acknowledged Helios as a solar deity, then he'd fade back in, yeah?"

Nico quietly watched Will as he exchanged words with Jason. There was a look of determination on his face, the same kind of look that he'd given Nico only weeks before during the battle with Gaea. That was one of the things that had caught Nico's attention - the sense of stubbornness gave him such a commanding presence that even Nico had done as he'd said.

But with it, came an odd sort of uneasiness. "Wait a minute, Solace, you're not thinking of-"

"I'll do it," Will confirmed, standing and facing Chiron. "I'll accept Artemis' quest. I'll go to Camp Jupiter and convince them that Helios is worth their time. I'll resurrect the sun."

"...I see," Chiron replied, fixing him with a look of concern. "You are sure?"

"Yes, sir."

"And you also agree to take the Hunter - Mena, was it? - along with you as per Artemis' request?"

"Sure do!"

"Alright, then. Decide who else will be going with you and then make the necessary preparations. It's best to leave for Camp Jupiter as soon as possible. We don't want to be without daylight for any longer than we have to. It'll ruin our strawberry crops."

On an impulse, Nico stood up and turned to Will. "I'm going, too."

Immediately, he felt everyone else's eyes on him. He wasn't sure what exactly had compelled him to stand and proclaim that, but he was already starting to regret it. But the face that Will was making now… Nico wasn't sure if the son of Apollo was thankful or horrified, but either way, there wasn't any backing out now. Not after speaking up in front of the entire group.

He sighed, allowing his shoulders to relax. "I'll go with you."

Will squinted at him, pursing his lips. "I don't think so, Spooky. You're not really in any condition to be doing any quests."

Nico glared at him in response. "Like you are? You've said yourself that you're a healer more than a fighter, and you have the bow and arrow skills of a clump of minotaur dung."

"Okay, first of all rude, and secondly, you were partially transparent until like two weeks ago."

"I'm fine now, Solace. You don't have to treat me like I'm going to break or anything. I'm going whether you like it or not!"

Everyone else kind of awkwardly fidgeted, glancing between the two as if they were watching a really intense rap battle.

Will frowned at him for a few more moments before sighing, raising his hands in defeat. "Alright, fine, but the second you show any signs of 'fading into the shadows' or whatever that nonsense was, I'm shipping you back to camp in an ambulance."

"Whatever," Nico replied, rolling his eyes as he headed for the door. "Come on, let's go and get ready."

Will nodded and started after him, briefly turning his attention to the Hunter in the back of the room. "Meet us at the Apollo cabin in like an hour?" He received a silent nod in response, then turned back to follow Nico out of the Big House.

Percy was really lucky that Nico was already out of earshot before quipping, "those two should just make out already."