Disclaimer: I don't own Trials of Apollo.

APOLLO III

An oath on the Styx
Again: You shall not go there
Forgive me, my son

The sight of his son so disoriented from something as simple as shadow travel cemented any trailing resolves Apollo might have had about taking his son's place in Tartarus. He was terrified at the idea of going back down there, especially considering the last time he'd been down there, but he knew that it was the right decision.

Will was too bright, too kind, too everything that Tartarus was the antithesis of, and if even a short trip to the Underworld was enough to disrupt him, albeit briefly, then Tartarus would destroy him.

Still, he had to admire his son's bravery as he pulled himself to his feet, flanking Nico determinedly, and stared down the two gods before them.

"We have to go." At least Nico didn't try and lie to his father, although Apollo caught the glare the son of Hades sent his way. The silent accusation of being a tattle tale was blunt, but Apollo was entirely unapologetic about it as he sent a sunny grin back at the demigods. Will's own look, less a glare, but still along the veins of a betrayed why, cut a little deeper, but he kept his smile up.

If it kept his son alive, he refused to have any regrets.

"I expressly forbade you," Hades reminded his son, his taller stature – because Apollo preferred the young adult look while Hades liked to be thin and imposing, and for no other reason – looming like the shadows he inhabited. "I do not care what your reasons are, I will not be disobeyed."

"Lord Hades." Apollo was not surprised that Will decided to speak up in defence of his son, but he did wish he hadn't; his safety, although admittedly the demigod didn't yet know it, was entirely in the hands of the god he was addressing, and causing offence would be fatal. "We're not going there out of choice. A prophecy-"

"Prophecies are not a clear cut command, son of Apollo," Hades dismissed him. "Even if my son fails to recognise that, I would expect better from you."

"It was spoken to us," Nico complained. "Apollo was there." Those dark eyes, inherited from his father although missing the flames of the gods, fixed him with a pointed look. "Did he tell you that?"

Technically Apollo hadn't, but he didn't think Hades would mind that he'd neglected to mention that little titbit of information when he'd given him the far more important fact that it had been directed at their sons.

The dismissive hand wave of his uncle suggested he didn't mind. "Irrelevant," Hades said firmly. "You were intending on disobeying me, and that I will not stand for. The troglodytes are not to be trusted, and I am insulted that you thought you could hide your dealings with them from me."

Pale skin blanched directly to white, Hades' son clearly not ignorant to his father's moods, although it didn't stop him arguing back. "You didn't leave me with a choice!"

The palace darkened further, until the only lights were those emitting from himself and his son. "Your choice would have been to obey me and ignore the denizen of the Pit attempting to lure you in and use you to escape," Hades told him pointedly. "Then the prophecy may never have been spoken at all."

Technically prophecies didn't work like that, and Apollo couldn't help shifting his weight where he stood, although he refrained from interrupting his uncle for the moment. He really needed stay on Hades' good side until this was all over and Will's safety no longer depended on the Lord of the Underworld's good wishes. Hades did not often have those.

"Well it has," Nico retorted, somewhat petulantly, and Apollo was starting to find himself wishing to shut the demigod up for his own safety; Hades' temper was vicious, like most gods', and quite frankly it was disturbing that he was permitting his son to speak to him like that. "We don't have a choice, now, so are you going to help us or make things even worse?"

"Any help would be very gratefully received, Lord Hades, Dad," Will interjected, grabbing his boyfriend by the scruff of his neck and forcing him to bow while doing so himself. Apollo couldn't even be mad that he was addressed second when he supposed he seemed less likely to smite them for impertinence right then.

"Help?" Hades scoffed, but Apollo decided he'd been silent long enough; now his son was involved in the conversation, he was going to play his cards.

He stepped forwards, letting his light shine a little brighter and forcibly inserting himself as the centre of attention. "I'm not here to help you, Will," he said, and found the look of dismay that crossed his son's face painful. Despite what he'd said before, when the prophecy was first issued, it was obvious that Will had been harbouring hope that he'd changed his mind, and seeing his son's faith in him take a visible blow was painful.

"Dad?" he asked, in a voice that was small and weak and a little afraid. It drove another metaphorical dagger into Apollo's essence, but he reminded himself that Will just didn't yet understand.

"I'm not here to help you because you are not going," he clarified, crossing the rest of the distance to his son and shrinking with every step until he was only a little taller than Will. His hands clasped his son's shoulders tightly.

"You want me to abandon Nico-"

"The Pit will destroy you!" He didn't mean to flare up quite as brightly as he did, but he felt Will flinch beneath his grasp – a too-tight grasp that was imprinting bruises that had to be painful on the fragile mortal before him but Apollo couldn't let go. "If you go, you will not come back, and I will not let that happen, Will Solace."

"Did you see that?" his son demanded, wriggling futilely against his grip, "or are you trying to scare me into abandoning Nico?"

"I am a god, Will," he reminded him, a little harsher than he meant to. "I do not try, I do." Not strictly true in every situation, but that was irrelevant right now. "And I will swear, on the River Styx-"

"Dad, don't you dare. You broke enough-"

"-that for as long as it is in my power to prevent it," because Apollo had learnt lessons about making promises that were impossible to keep, "you will not step foot inside Tartarus."

The oath sealed with a crack of thunder, rolling around the palace with the deafening acoustics that could only come from making such a promise so close to the borders of the river itself, and Will's face turned as pale as his boyfriend's.

"Dad, no," he pleaded, "you can't do that. You can't make me stay behind."

Apollo sighed and used his too-tight grip on his son to pull him into an embrace, wrapping his arms tightly around the fragile teenage body and resting his cheek on the blond waves Will had inherited from him. "I can and I will," he said firmly. "I meant what I said; you are not going in there. Lord Hades has agreed to house you here until the quest is complete," he informed Will. "We'll have to do something about the lack of food fit for mortals, but you'll be safe within the Underworld."

"But Nico!" Will protested, still wriggling in a desperate attempt to get free, the pain in his voice making Apollo's entire being ache. "And the prophecy-" he added, clearly an afterthought but one a frantic one, as though he thought bringing Apollo's own domain into the conversation would somehow change his mind.

Apollo shook his head and reluctantly released Will from his hold, embracing the pain as Will immediately grasped for Nico's hand, both demigods going white-knuckled as they clutched each other tightly. If only he could replace both of them, spare Nico the trauma as well and keep both demigods safe and out of Tartarus, but the prophecy was clear that one would not be enough.

Still, "I think I make a pretty good claim to sunshine," he commented, trying for levity and hoping it didn't sound quite as flat to his companions as it did to his own ears.

"But-" Nico interrupted, and Apollo turned to him with a raised eyebrow, "what about the Ancient Laws? And, I can't say I'm not happy Will's going to be safe, but… no offence, Apollo, I don't think you'd keep me as sane as Will would."

Behind Apollo, Hades let out a dry laugh that had even his hair standing to attention, no doubt because Hades was still in his godly height and the sound affected those of human stature differently. "You appear to be misunderstanding, my son," the Lord of the Underworld said. Apollo glanced over his shoulder to see his uncle approaching them, shrinking in size himself until the four of them were all, near enough, equal.

Hades was still a head above the rest of them, because of course he was.

"Have I not made it clear enough?" the older god demanded. "Nico, my son, you are not returning to the Pit."

Apollo frowned, a little confused and very disconcerted. Two of them had to go down – if he replaced both of them, that really did break the prophecy; it was quite explicit that two were to descend to Tartarus, and no matter how amazing Apollo was, he still only counted as one. Not that he wanted Nico down there in the slightest – if it was possible to spare Nico as well, he would have jumped on that loophole no matter how small, prying it open with his bare hands if he had to, but there was only so much he could do about the darkness part of the prophecy, and Nico was the one of very few who would likely even count, let alone be willing, as much as anyone would be willing to go to Tartarus. He was also the one that had intended to descend into Tartarus even before the prophecy was issued, to rescue the titan.

Apollo had no doubts that convincing Nico not to go into Tartarus for the sake of the titan would be a waste of breath – Will had not managed to convince him, and if he couldn't, who could?

"You and your boyfriend will be remaining in my palace," Hades continued. "My brother cannot enter here. As for the Ancient Laws… There are loopholes."

"Such as?" Will asked, rubbing at his shoulders and wincing. Apollo reached out and brushed his own hands over the hidden bruising, trailing healing touches across them. His son didn't even glance his way in acknowledgement, focused instead on Hades and Nico in a way that screamed avoidance as much as respect for the older god, and Apollo suppressed a wince – it wasn't like he didn't deserve it.

"Those do not concern you," Hades dismissed, which Apollo could immediately translate as we're still working out how we're going to talk ourselves out of trouble if we get caught – or at least, that was the stage he was at. If Hades had already worked something out, that would be useful to know. "What does concern you is that both of you will remain here, while your father and I investigate what necessitated this prophecy to be spoken in the first place."

What?

Had Apollo heard that right?

No, he must have been mistaken.

But he was a god, he had perfect hearing. He didn't do mistaken.

But what could possibly have prompted Hades to decide that he, too, would take his son's place on the quest? It was a good thing – a really good thing – in that it meant Nico would also not be entering the Pit and would instead be safe and still with Will, but Apollo had never, ever, expected Hades volunteering to go in his stead, not even with all the foresight in Olympus.

"What?" Nico choked, unknowingly echoing Apollo's carefully-hidden surprise. He was glad for it, the son keeping his father's attention firmly on him and buying Apollo time to make sure his own shock wasn't evident on his face. The demigods would never notice, especially as both of them were pointedly looking anywhere but him, but Hades might.

"I will not repeat myself," Hades said firmly. "Do not even think about attempting to make your own way to the Pit."

"But-"

The shadows surged around them, flowing over Hades' son, and when they receded the demigod was gone.

"Nico!" Will stumbled forwards, almost falling over as his boyfriend's hand disappeared from his own white-knuckled grip, before seeming to realise that he was alone in the presence of two gods and visibly collecting himself. "Where is he?"

His voice didn't even shake as he addressed Hades, and Apollo was torn between being proud and terrified.

"I sent him to his room," the god replied, seemingly unconcerned by Will's attitude, to Apollo's private relief. "He will stay there until I release him."

"And… what about me?" Given that Will was clearly upset with him, Apollo was slightly surprised – although relieved – when his son's eyes flickered over to him, as though trying to reassure himself that Hades wouldn't dare do anything to him while his father was there.

Hades would, but that was beside the point.

"What about you, indeed," Hades mused. "Apollo, how is your son going to survive his stay? There is no mortal food in my palace."

"I have food," Will started, reaching for his pack, but the problem with mortal food in the Underworld was that it didn't last. Will might be able to eat for a day, but after that, it would all have perished and he'd be risking starving to death.

Apollo ignored his son's words and found his eyes meeting Hades', the fires of which were flickering in clear amusement. Trust his uncle to be amused by his predicament – it was all his fault, anyway. If Hades hadn't decided, for some unknown and incredibly bizarre (and rather concerning; Apollo didn't like it when his brethren behaved surprisingly) reason that he, too, was going to replace his son on the quest, then he could have subtly provided mortal food daily. It was still much, much, better that Nico's place was also being taken by a god, but it left Will's survival in the Underworld rather less secure.

It was summer, and Persephone was enjoying the bright warmth of the sun with her mother for the next month or two, so she'd be no help, either – not that Apollo was quite sure he trusted the goddess with his son. He didn't really trust Hades with him, either, not really, but at least he had the leverage with Nico. In terms of safety, both from the gods and from Tartarus, Hades also leaving the palace and Will remaining with Nico was the best possible scenario – but it still created the food situation.

"We don't have all eternity," Hades drawled. "My brother will no doubt notice your absence soon, Apollo." Apollo knew that; he still had a sliver of himself in the sun chariot, attending to his primary duty and the one in his father's immediate attention, which would stay there until the last possible moment – he was not so foolish as to think he could take on Tartarus at anything less than full power (and yet demigods kept ending up down there and almost-dying) – but the rest of him was collated into his current form, ignoring the rest of his duties. His father would notice, and soon.

"Dad?" Wide, blue eyes looked at him, uneasiness clear in their depths. He couldn't blame Will for being nervous in the face of Hades, and part of him twisted at the fact that, despite being upset with him, Will still looked to him for help. He didn't deserve his son's faith at all.

"If you don't do something now, I will," the other god promised. "Don't waste my time." It wasn't even a threat; Apollo could see his raising hand, and panic blossomed. He didn't know what Hades had planned, but he heavily suspected that it wouldn't actually help Will; if Hades trapped his son in the Underworld, it would simply ensure that Nico lived down with him all the time. Will didn't have to be dead for that to happen.

"I've got it!" he protested, returning to his son's side and resting his hands on Will's shoulders. If his positioning served to place him directly between his son and his uncle, thereby getting in the way of whatever Hades was about to do and buying him a few more seconds, well, that was just a coincidence.

It also would buy only seconds. They were in the heart of Hades' domain; Apollo could only do so much against his wishes, and it wasn't too late for his uncle to throw him out and drag Will down into Tartarus if it for some Olympus-forsaken reason pleased him, oath on the Styx or not. His thoughts raced, discarding options as fast as it generated new ones.

The overwhelming instinct was to transform him into something that didn't need sustenance. Some form of cave-dwelling plant – Olympus knew there were enough of those in the Underworld, and Nico could be easily relied upon to keep him alive – but there was a nagging thought in the back of his mind that stayed the action.

No-one Apollo loved had ever been able to turn back from being a plant.

The swish of tortured-soul robes on the obsidian floor heralded Hades' approach, and Apollo realised he was out of time.

"Will," he said quietly, cupping the side of his son's face with one hand. "I'll see you soon."

The answering, confused, Dad? was overridden as he started to sing, a quiet, peaceful number that he steadily eased an increasing level of power into. Behind him, Hades' advance silenced, which was all the attention Apollo cared to give his uncle right then as he spun a delicate web of healing magic.

It wasn't ideal; it was far from ideal, but Apollo's options were severely limited – no thanks to his uncle. He couldn't just sing Will into an enchanted sleep, partially because that was more Morpheus' domain than his and opened his son up to dreams which could be easily invaded by any god with intent, and partially because that didn't actually fix the food issue. It had to go deeper than that, staying firmly within Apollo's own domains, and there was only one type of sleep he could induce that was his.

Will wavered in front of him, eyes drooping as the song washed over him, and Apollo pulled him close against his chest, guiding them down to the floor of Hades' throne room as his son's weight grew heavier against him. Not that Will was heavy, to a god. He might have been a feather for all the difficulty he posed Apollo as he slumped against him, but Apollo chose to feel the warm weight of his son as he sank away from the waking world.

The song didn't stop even as Will lost the battle to stay awake, falling limp in Apollo's arms. He adjusted his grip until his son was cradled protectively against him, but kept singing, drawing Will down further and further.

It was risky; not so risky that Apollo feared getting it wrong, but risky enough that the feeling of his son's pulse slowing to extreme lethargy sent a jolt of fear through him. Will's head lolled limply against his shoulder, his light fading away to nothing as Apollo's power washed over him and ran through him, soothing every part of his body.

He finally let the last strains of melody fade away as Will's body slowed, his chest rising and falling barely perceptively at a rate that on a mortal should be a major cause for concern. Apollo's own concern was only mitigated by the fact that he had done this, and that he didn't make mistakes. Not with his son's life.

Growing slightly, enough that Will's lanky growing-teenager frame fit perfectly in the cradle of his arms, Apollo pushed himself to his feet again, turning to face his uncle. Hades raised an eyebrow at the unconscious boy, already matching Apollo's new stature, plus his customary extra head of height. "I'll leave you to explain what you've done to my son," he said. "I doubt that was what he had in mind for keeping William 'safe'." The other god sounded amused at the idea of Apollo facing Nico's wrath, which didn't surprise Apollo in the slightest.

"Where is Nico's room?" he asked, resisting the urge to look away from Hades, even if it was just to glance down at his son in his arms. He could feel Will's vital signs clearly, on the cusp of too slow but in no danger of slipping over the edge.

"I rather thought you'd turn him into a flower," his uncle continued as though he hadn't spoken. Apollo grit his teeth, reminding himself that his son was still going to be staying in the Underworld, and that even if Hades was going to be temporarily vacating it, it wouldn't do to agonise him, just in case. "Both you and my wife seem to have a fondness for doing so."

Apollo had to fight to keep the frown off of his face. "I thought Nico would prefer not to be dating a flower," he said, trying to keep his tone light but aware that there was something sharp glinting in the depths of his voice. Hades' smirk told him that his uncle heard it. "Nico's room? I believe you were the one to bring up the time pressure, uncle."

Hades snapped his fingers and a skeleton materialised. "Show Apollo to my son's room," he ordered it.

The skeleton bowed to the god, bones rattling in A Minor as it did so, before heading through a door to the side of the throne dais. Apollo watched it go, before a noise caught his attention. Hades had a raised eyebrow. "Go," he ordered. "I will meet you there once I have put some affairs in order."

It made sense that Hades had to sort some things out before leaving his domain entirely. Apollo had had time to plan and put in contingencies, but Hades' decision had been, well, it appeared to have been a spur of the moment conclusion, and his domain was far, far more involved than any of Apollo's. He nodded, and followed the skeleton.

Here's our second narrator for the story! Hades and Apollo will alternate every two chapters, and yes in the spirit of TOA, every one of Apollo's chapter titles will be (probably bad) haikus. There were a few guesses regarding what's going to happen here, and for those of you for whom "Monopoly" means something - sorry, you were wrong!

Thanks for reading!
Tsari