With the ATLA hype train, I suppose it was inevitable that I end up here, with this PJO/ATLA crossover. This idea had been playing in my head for some time now, and it took some external inspiration to finally set together the plot. I hope it delivers.

It's very, very AUish on both sides, so expect to see many changes that maybe you might not be comfortable with.

A lone figure crossed through the streets of Olympus, leaving a trail of hushed discussion through her path.

Even someone arriving for the first time would realise the magnificence of the city, even in its dire state. The Second Titan War had torn apart much of its intimidating perfection, but the splendour was for all to see and be in awe of. Beings of all kinds filled the spaces, whether they were travelling, or working on the city's repairs.

In itself, a figure moving through the citadel's hefty crowds was not a cause for concern. Especially on the day of the solstice, when the council of gods met and beings and spirits came to share their concerns. Or more commonly, to take part in its riveting celebrations. But this deity, black as tar caused heads. She ignored the flamboyant partygoers, and headed straight for the chamber where all of significance was discussed.

"Lord Zeus," she bent low in a formal bow, unperturbed by the curious looks being sent her way. The king of Olympus racked his brain for any reasons the goddess of hatred would have for an audience. She was mostly concerned with herself, barely ever leaving her. Seeing her on Olympus was cause for unease, as best as he did to hide it.

"Styx," Zeus said by way of acknowledgement, "speak, what is it that you wish from me and the council?"

She straightened, looking straight into the king's cold eyes. "I am here to collect my debts, which I had forgone for the duration of the war."

Zeus frowned, "What debts do you presume I owe you, Styx?" he rumbled.

A few of the Olympians leaned forward, some with worry, some with wonder. The look Hera sent, ever the picture of authority beside her husband. would have caused any lesser being to flinch. But Styx only huffed a laugh, full of the scorn and disdain that she was renowned for.

"What debts?" she asked. "Oaths sworn upon my river have been broken. Debts you owe me."

There was a pause - a minute, or a few more, it was hard to tell. Zeus's jaw clenched tight, and the clouds began to thunder. "What is it that you want?"

The goddess flicked her eyes around, observing the spike of interest in the room with glee. Hera had relaxed considerably, although she still maintained her regality. "Over twenty years ago, you, and later your brother," she cast a glance towards a furious sea god, "sired half-bloods. Which both of you agreed not to have, on my river. And the Styx does not take these transgressions lightly."

"I will repeat again," a clap of thunder followed his words, "what do you want?"

"Why, is it really hard to tell, Zeus? I wish for my debt to be returned," malice intonated in every word, "Retribution. Adherence to the oath, as it should be. I shall claim those two bastards of yours, to make this right."

"You want to take Thalia's life?" he asked. "This is unreasonable, and totally unacceptable. Much time has passed since she was born. It has been too long to lay claim. The demigods have lived and fought for the defence of Olympus for these past few years. We cannot take their lives when they have served us with so much dedication. It will not… go over well."

Murmurs of agreement followed the king's statement.

"On the contrary, Zeus, this is the perfect time. The prophecy has come to pass, and the heroes have played the part the Moirai set for them. And now when all is over, they belong to me."

Zeus began to stroke his beard, deep in thought.

"You will not intimidate me to change my stance, Olympians," she filled the space in conversation, regarding the glares sent her way by some Olympians. In particular Poseidon and Artemis. "For these broken oaths to go unaddressed for years is a slight against the sanctity of my river. Especially after one of them sullied it with his disgusting hope and love." The hearth flickered for a brief moment, growing wild and erratic. "Words cannot convey the disrespect it is for something of mine to take from me."

"I, for one, will not agree to this. My son does not deserve death. Especially not death by the Styx."

"And I will not see Thalia die after teaching her the ways of the Hunt. She is a sister to me in all ways that count."

"Both of them are symbols of Olympus among the demigods. Having them die after serving in an entire war about neglecting demigods is counter-productive in all ways imaginable."

"Ah, I couldn't care less, but that's no way to go. Brats have got a lot of fight in them. They should die fighting. Preferably against me."

"Yes," Zeus finally spoke, "Thalia is a hero. She shall not die so easily after successfully fulfilling the prophecy. It goes against everything Olympus stands for."

"It is of no importance to me whether they fulfilled the prophecy or not," Styx replied, "they are not supposed to exist, and this existence needs to be mitigated, lest it upsets the balance of Fate. And I have had enough of this issue troubling my waters till now. It corrupts me, and it will not be long before the effects make their way to you."

No one spoke up. The lighting grew dim, and the faint sounds of lutes and flutes could be distinguished from the world outside the throne room.

"If it makes this easier, they will not lose their lives when they enter the Styx. I will swear to that."

A smirk played on her lips with all the attention that statement garnered.

"And what will happen to them? Will they be forced to suffer inside your foul river for all of eternity?" Dionysus entertained with a disinterested drawl.

"Explain," Zeus looked ready to smite Styx, and he might have if he could.

"The recent upset that these unpunished transgressions created needs to be balanced. And the best way to mitigate this is by sending them to where they can restore the balance."

"And where is it they would be sent to?" Apollo was quick to ask. And for a brief moment, all looked to him.

"I do not know where or what," she began, regaining attention from the audience, "All I know is that is somewhere other than here and it will help cover the lapse in my duties. And that will do for me."

"But this is vital information if it has something to do with the balance of our world. We must know."

She shrugged. "You can ask the fates if you want to. Shouldn't you be able to tell with your entanglements, Apollo?"

Apollo remained silent, gaze faraway from the room. And Zeus took his cue. "If what you say is true then I believe the decision is obvious." Poseidon shot to his feet, but Zeus continued before he could protest. "However, I will need definite proof of this… upset, as you call it. And that the only solution is to deliver my daughter, and Perseus, to you. Otherwise, I will refuse your demands. Do not pretend that there aren't any alternatives to settle a broken oath, Styx. We all know you ways. This petty revenge is not more important than the peace these heroes have brought."

"Very well. There is a lot to see - if you bother with investigating the Underworld."

"Yes. We will. Now you are dismissed."

All knew the goddess of hatred had won then and there, and she knew she was leaving the throne room as tense as it was when the bolt had gone missing.

The wrong shall be righted. Balance shall be restored. Dreams and hopes, cleansed from the soul.

The moment he regained a sliver of consciousness, his head throbbed in pain. Why does it feel like I was wrestling with the Minotaur? Percy had not ever wrestled with the Minotaur, but he had wrestled with Clarisse la Rue. And in his opinion, they must come close.

He could barely make out some words about someone being awake, but he couldn't tell who they were talking about. Or who said them.

What was the last thing he did? He couldn't remember. Had he gone head to head with a titan? Wouldn't be the dumbest thing he did.

Jets coursed through his veins, hitting all parts of the body and directing their feelings the brain, oh, my head hurts. It really, really did. There was something said about hurting in the background. The people were noisy.

His eyes opened, but all he could see was blue. A pale blue, which swirled in his vision like a hurricane.

"Can you hear me?" he heard someone say, and for the first time he figured they must be talking to him. The voice was very gentle. Definitely not… someone. With blonde hair. He might've smiled, but it was difficult to with his head hurting.

"Y-yes," he rasped drily. He felt an intense need for… a thing. Which his mind couldn't grasp. Oh, it hurt. And why was it so cold? It felt like he was surrounded by ice and water. Ah.

"Water," he rasped again.

"Yes, you are here in the water tribe," the same sweet voice said.

Huh?

"Wha… water," he pointed to his mouth.

"Oh, I am sorry. Let me get you some water."

The beverage went down his throat, and with it some semblance of his surroundings.

The place was indeed ice - like an igloo, but like an actual room in an actual house. What are the odds? He felt warm in the fur that was wrapped around him. And the girl attending to him was pretty - white hair that otherwise would have said suggested age, but on her it was clearly fitting. A crown for royalty.

"Uh, thank you," he said after realising he hadn't said anything.

She dipped her head, "your welcome."

His head still throbbed, but not as painfully as it had earlier.

"Um, who are you?"

She smiled, gentle and kind like all her mannerisms. "My name is Yue."

Yue. Nice name, he decided. Different. "I - how did I get here? I don't… remember coming here. Or what happened… can't remember much right now." At least not as long as thinking hurt.

"You were found floating a bit too far out from the shore, unconscious," she looked sympathetic towards his plight, "you were almost dead."

That sent his mind reeling.

"Thankfully the men found you during one of the fishing trips. La knows what would've happened if they set out later as scheduled."

Something about that statement felt really wrong, but Percy could only be relieved that he wouldn't be taking a trip to Hades the hard way yet.

"And where am - where are we now?"

She smiled again, sincere and as truthful as one could be, "You are now in the magnificent city of Agna Q'ela, capital of the Northern Water Tribe."

The words registered. They smacked him across the face. And then it registered that he most definitely did not recognise this place.

Oblivious, Yue continued, "What is your name, and where are you from?"

Where in the world have I found myself this time?

I will admit that the Styx idea was borrowed from another PJO/ATLA crossover called Avatar: Legend of Perseus.

If any of you are interested, here's a link to my Discord server, where I often post updates and teasers, and is the best place to ask me anything regarding my works.

/cyrxRW9J