Here goes; my first non-kotlc oneshot! This one is gonna be PJO, from Nico's POV, so if you haven't read the books (including Heroes of Olympus) then this contains mild spoilers for Nico!

Here we go-

The words echoed through his head, but they didn't make sense.

"What do you mean, he's gone?" Nico demanded, fear coursing through his body.

"He just... disappeared." Thalia's face was tight, her lips pressed together. "We've been looking for a week. Annabeth said he kissed her goodnight and went to his cabin, but he was gone in the morning. We've asked his mom and Paul, and they have no idea."

"He wouldn't just... leave," Nico said, ignoring the twinge of pain that went through him hearing about Annabeth and Percy kissing. "Was he taken?"

"Impossible," Thalia spat. Nico knew she wasn't angry at him, but he almost took an involuntary step backward before remembering himself and holding his ground. "The camp couldn't let anyone in; the borders are strong, and there was no hint of any forced entry. Whatever happened, Percy left himself."

"Or a god took him," Nico reminded her. "They could teleport him out, they're allowed in camp."

"The gods are silent. Why the heck would they take Percy? He's the special one, remember?"

Nico knew Thalia was a little bitter that she hadn't been the one of the prophecy. Even though it was her choice not to age so she wouldn't have to face it, and she was the new leader of the Hunters.

He understood.

Maybe bitterness was a family trait.

But at least Thalia was the daughter of Zeus, the right hand of Artemis. She was accepted. She had friends and family and-

Nico pushed his wordless anger out of his mind. There were more important things to focus on.

"No one has any idea? He didn't leave on some kind of quest?"

"He's not the type, Nico. Percy may have the curse of Achilles, but he knows better than to leave camp without telling Sally or Annabeth." Thalia gripped his shoulders, and Nico flinched out of her grasp automatically, moving away from the contact. "You were kind of our last hope. Have you seen anyone? Has Hades said anything?"

Nico wished Hades would speak to him, but even the Lord of the Underworld had chosen to shut his trap. The one time Nico didn't want his father to leave him alone and stop bothering him about his potential and how much better his sister would've been, he vanished.

So he shook his head. "I'll keep my eyes out for him."

Thalia nodded, her face falling with disappointment.

Just like everyone who talked to him.

...

Before:

"Remember this route." Hades never liked to elaborate, but this was a little vague even for him. Nico go the sense that he was walking through an endless tunnel, even though the space was wide open in the daylight.

No one paid attention to the skinny, dark-haired kid and the middle-aged, pasty-skinned man leading him around the city. In fact, they paid so little attention Nico was starting to wonder if they were invisible.

"Here." Hades stopped so quickly and smoothly that Nico almost smashed his face into his father's back; which wouldn't have exactly upped his points with the unforgiving god. He stopped himself just in time.

"What's here?" Nico asked impatiently. Sure, the highway tunnel felt a little wrong, but there were probably just monsters camped out inside. Surely Hades hadn't led him all the way here to fight a bunch of monsters? Nico did that plenty daily.

Being a kid of one of the Big Three attracted a lot of monsters, even on his own. Nico had barely survived all these years.

"Look," Hades told him. "What do you see?"

Nico started to say this whole trip was pointless, but a warning glance stopped him, and he glared sullenly at the two tunnel entrances peeking through the cliff, with a cement wall jutting from the hillside that looked almost like a bunker. He felt a spark of wrongness go through him, stronger than any monster.

When he looked back to ask his father what it was, Hades had disappeared.

...

Nico waited impatiently next to the Pluto cabin for Hazel.

She was late, and this conversation wasn't something that could be spoken quickly. Without meaning.

Especially since the camp was buzzing with rumors about a new arrival.

A Greek.

They could be wrong (after all, Nico hadn't been approached by anyone to be told; no, he'd heard from passing by a circle of ghosts whispering furiously about the Graecus who defeated two gorgons by using the river. The demigod with dark hair who was a son of Neptune, but arrived carrying Juno).

But Hazel was late.

Finally, he heard two pairs of feet clomping up the path towards him (Frank, perhaps?) and turned to face them.

But instead of seeing Hazel and Frank, he was greeted by a too-familiar face, with sea-green eyes and dark hair.

The face that haunted all of Nico's nightmares and consumed most of his waking hours.

Emotions flooded through Nico's body, and it took all of his self-control not to burst into tears or start screaming with anger (or perhaps happiness).

But how could Percy be here?

"This is Percy Jackson," Hazel said obliviously, as if Nico's world hadn't just flipped completely around. "He's a good guy. Percy, this is my brother, the son of Pluto."

Nico knew his face felt a hint of the panic that took over him as he realized what he had to do.

But he was the son of Hades. (Pluto, he reminded himself. Here, he was the son of Pluto) 

And Percy was staring at him curiously. He didn't recognize him.

So Nico stuck out his hand, keeping nothing but mild curiosity on his face, hoping no one noticed the way his fingers shook.

"Pleased to meet you," he said calmly. "I'm Nico di Angelo."

...

"No."

Nico wasn't sure if the word came from him, or even if he'd said it out loud.

All he knew was Annabeth and Percy, dangling fifteen feet below the edge of the floor.

Above Tartarus. Literal Hell.

Nico shook away the flashbacks that plagued him (the broken glass dug into his knees as he stabbed the last monster, spitting out the fiery air) and reached into the pit fruitlessly, trying to reach for the couple that hung too far down for anyone to reach.

Annabeth's mouth moved, her terrified eyes catching Percy's. It was her gaze that scared him the most; Annabeth was the strongest, smartest, most fearless person he knew, and if she was giving up hope, then there was no way out.

"Never." Percy's voice was barely audible. His fingers grasped the ledge desperately, and Nico choked with fear, his eyes filling with tears as he reached further down, seemingly miles away from his body.

"The other side, Nico! We'll see you there. Understand?" Percy shouted, his voice crackling.

Nico's face stretched with shock and horror. "But-"

"Lead them there! Promise me!" Percy yelled, his sea-green eyes locking with Nico's as his arm trembled in the air.

Nico's mouth moved without him telling it to. He was never able to refuse Percy.

"I- I will."

Percy's arm loosened, his face relaxed slightly, and Nico saw with horrifying certainty what was about to happen.

He screamed, his yells matched by Hazel as they watched Percy's fingers relax on the ledge.

As Percy and Annabeth fell into the endless darkness below.

...

Clytius was dead.

They'd won.

But why did Nico's heart still feel like it had fallen through his stomach?

Maybe it was because Percy and Annabeth were standing so close that their shoulders were touching, and they kept on looking at each other in such a sweet way that Nico's stomach dropped further and further every second.

Everyone was celebrating, but Nico stood by himself, in the shadows, as always. He watched Percy and Annabeth and the rest of the seven embracing, and he couldn't stop the bitterness from taking over him.

He was grateful that everyone had survived. He was beyond thankful that Percy and Annabeth were out of Tartarus, but something about seeing the seven together made it even more clear that he was separate.

Unwelcome.

Hazel beckoned him over, and he dropped a reluctant kiss on her forehead as she brushed her finger below his eye, and he realized his eyes were stinging.

But there was no time to talk or comfort each other, because the floor was collapsing beneath them and god he couldn't go back down there.

He knew that Percy was anxious by the furrow in his brow, his clammy hands as they linked hands and faded away into the shadows, the familiar coldness seeping through Nico's skin.

He dropped Percy's hand as soon as they materialized above ground, ignoring the memory of their connected hand as he tipped his head back, safely in the sun.

He breathed in the rays, ignoring the happy shouts of those around him.

Light wasn't his favorite thing, but he'd had enough darkness for one trip.

So yeah

That-

I love Nico more than words can express, by the way. He's my second favorite character in all of Rick Riordan's work (Leo's first, of course, and Alex is third) because he's just awesome-

I've had this idea for a while, just like most of my ideas.

Poor Nico. He's been through so much that we haven't even seen, it's insane.

Anywho

Comment below, etc, all that jazz!