Author's note: Enjoy!

Disclaimer: The following characters belong to Rick Riordan and this story derives from his original works, storylines, and world. I am doing my best to stay informed, as a fan and creator, about the critical readings on PJO/HoO and appreciate any feedback on those topics about my work so that I can continue to grow and make fandom a safe space.

Warnings: NA

On Disappointing the Styx

On the rare times that he was on Olympus, he liked to take his time to visit the gardens and lookout points across the mountain. Yes, the dallying unnerved Zeus, but Poseidon genuinely liked taking his time to make those rare visits worthwhile and to remind himself that Olympus was beautiful, even if he was usually there to argue with his family. Not everything he did was to annoy his brother, after all. Some things he did to bother Athena.

He was standing on a bridge overlooking a multistoried waterfall with the bluest water imaginable, the way it had been blue and salty and untouched when the world had begun and he'd first inherited the seas. As he watched the water rushing down, someone came to stand next to him.

"You usually don't take your time before going home," Poseidon told his oldest brother. Hades leaned against the railing, the mist from the waterfall settling on his long black hair. He was wearing simpler robes than he wore at the Summer Solstice meeting and his arms were bare of any gold bands or jewels plucked from the bowels of the earth.

"I usually don't," Hades said, looking over the water. "And you are not usually one to break promises."

He answered in the dialect so old it wasn't Ancient Greek; so old that even the second generation of Olympians had never been able to master the tongue and its sounds, to Athena's eternal frustration. It was the language he remembered speaking in the few memories of childhood that he had, and there was something comforting to it even considering the words Hades had used it to speak.

Poseidon didn't dignify that with an answer quite yet. He had said Perseus Jackson's name that summer more than he had in the first twelve years of the boy's life. The solstice meeting had been no exception and Poseidon hadn't been particularly surprised by any of the answers—Ares' embarrassed silence, Athena's eloquent and thinly-veiled insults and musings on the prophecy, Hera's disappointment, Aphrodite's pleased soliloquy on the power of her domain, Hephaestus' complete lack of interest… Hades had been the one to hold his tongue, as he often did during meetings. Poseidon should have known that his brother would find him alone.

"At least I wasn't first," Poseidon said. It was the best defense to Percy's life that he could maintain, and sometimes the only one which was particularly useful against Zeus. He isn't the first. I am not the first to have broken this oath.

"As if there is any pride in outlasting Zeus in an event even remotely related to celibacy," Hades said—which was a fair point. Poseidon might have smiled if he hadn't been expecting more anger from his brother; the only one who remained who had not disappointed the River Styx.

"I appreciate that you have not released your worst on the boy simply for existing," Poseidon said simply.

"For now," Hades said.

"For now," Poseidon admitted. Hades was the less rash of the three of them, but Poseidon doubted that Percy was in any real trouble vis-à-vis this particular uncle.

"I did meet the boy," Hades said.

"And?" Poseidon asked.

"He is stubborn," Hades said. "Impatient, impertinent, and bold. Protective, dedicated, and insubordinate. Had you not claimed him, the mystery would not have lasted long either way."

Poseidon nodded. He had known this too. Sally had warned him, on one of the rare occasions where she had allowed him to establish contact. Percy had been younger then; Poseidon suspected that the problem had only gotten worse and the similarities more pronounced since.

"He is my son," Poseidon said. "I do not expect any more sympathy from you than what Thalia Grace earned in her short life, but I would implore you to be merciful. It is not the boy's fault that he was born."

"It never is," Hades said—which seemed like a non-answer, but so be it. Hades leaned against the railing some more. "I suppose it wasn't his mother's fault either."

Poseidon hesitated.

"No," Poseidon said. "No, she made no oaths to break. Those were mine and mire alone."

"Oh, I know," Hades said. "Believe me. I, of all the pantheon, know."

Poseidon examined his brother to try and gauge how boiling hot the anger under his skin was. When Thalia had been born the two of them had been outright incensed; furious that Zeus had broken the oath that he himself had formulated and devised. Hades had been the most furious given all that Zeus had done to push the prophecy into the future when they had first sworn their oath. So furious, in fact, that Poseidon had seen no reason to do anything other than step back and watch his brother carry out his own form of justice with revenge and Maria di Angelo's name on his lips.

"Your son went to the underworld to rescue his mother," Hades said.

"He did," Poseidon said. "I am sure he would do it again."

"I saw him in the moment," Hades said. "Believe me, he would. Not only that but you should consider yourself very lucky that he finished the quest you had sent him on instead of the quest which he truly cared for. There was a light in his eyes that made me think he might not."

"Yes, and then where would we be?" Poseidon said. "What would you have done, had he taken his mother and let your helm be lost?"

"That is besides the point."

"Well what is your point?"

"Prepare for a time when his mother finds himself in my realm not as collateral and not to push against you, brother, but because she is put there by somebody with far less control than me over where the souls of mortals find themselves."

"Speak plainly, brother," Poseidon said, feeling the ichor in his veins boil as a feeling of defensiveness bloomed in his chest.

"Zeus, centuries ago when some of our children were aging out yet, did what he could to delay the prophecy," Hades said.

Poseidon did not force his brother to say more on the subject or, Fates forbid, Maria di Angelo's name. He simply nodded.

"Dark enough things are stirring for our brother to grow bolder and more careful," Hades said simply. "Neither of which would bode well for Sally Jackson."

Poseidon arched a brow, somewhat surprised by his brother's directness although he knew Hades was right.

"She has stepped away from the world of the gods some time ago," Poseidon said. "She has always put Percy first."

"Yes," Hades said. "I met her, you know. She was a remarkable woman."

"A queen amongst mortals," Poseidon said softly, repeating what he had told Percy seemingly moments ago.

"I will not disagree," Hades said. He leaned away from the bars, stretching his arms. "But you yourself admit that she is mortal."

Poseidon arched an eyebrow and met his brother's eyes.

"It is a suggestion," Hades said. "Not a threat."

"I will not buy your peace," Poseidon said. "But I will listen if you are here to ask for something."

"My children, Nico and Bianca," Hades said.

"Maria's children," Poseidon said. His brother nearly winced at the name.

"Maria's children," he said.

"Aren't they dead by now?" Poseidon asked. "Dead or old—ancient by demigod standards?"

"I put them somewhere safe," Hades said. "Somewhere out of the way. Time was not a concern."

"Understood," Poseidon said, though he didn't know—or, truly, care—what this place his brother spoke of was. He would find a way to find out if it became relevant.

"If you and Zeus have both broken your oaths and brought children into this world, then I expect mine to be allowed to live untouched," Hades said. "Should they reenter the mortal world."

Poseidon nodded.

"I can see that," Poseidon said.

"That is not an answer," Hades insisted.

"Then you have my word that I will not go after them," Poseidon said.

"And should Zeus try to reopen old wounds, will you stand by the sanctity of my unbroken oath?" Hades asked.

"Do not push your luck brother, I have my own qualms and problems with Zeus," Poseidon said.

Hades bowed his head and walked off the bridge, back into Olympus. His shadow seemed especially dense and especially wide as he walked, and though he quickly joined the crowd he did not disappear into it as nymphs and godlings froze in their steps to make him room and let him pass.

Poseidon looked back to the water.

WC: 1426