PERCY

Percy didn't know where the others had gone but he didn't really have time to worry about it as Triton was at present trying to use him as a punching bag.

He'd heard that's what siblings do, but something about the way Triton was attacking felt far from brotherly. The now fully fledged trident had skittered away somewhere into the blackness and Riptide had been thrown from his hands when he fell. It had yet to reappear in his pocket and it was all he could do to dodge the merman's punches.

The ground shifted again and he lost his footing, catching a blow to the rib that sent him hurtling into the ground like a cannon blast. He gasped and coughed through the stale air as he tried to stagger up again before Triton came back for more. For someone who was used to swimming around with a tail, he was a surprisingly good kicker.

"I am going to show you what happens to those on the wrong side of wars, Jackson. First I'm going to show you, and then I'm going to show Poseidon what it means to be a real god of the sea." Triton's voice echoed unhappily across the chalky expanse, painful to Percy's battered head and filled with menacing conviction.

Percy had no doubt the immortal meant what he said.

"It seems to me," he said through gritted teeth, "that there can't really be a wrong side to a war if everyone thinks they're on the right side."

"Well then I should be happy to enlighten you."

"I'd like to see you try." Percy felt the pressure of metal inside his pocket and automatically drew the pen in front of him. Now they were on more level ground.

If only the ground knew that.

The gravel lurched and swayed beneath him and he caught sight of Leo stumbling up from the wall of the breach that had opened up a few hundred yards away. The younger boy whipped his head back and forth, looking for something, looking for the others, then Percy lost his footing and Leo disappeared from sight.

Triton advanced on him, unfazed by the quaking, a smug expression across his green face as he glared down at his mortal half-brother.

"I know why you're doing this," Percy said as he dodged Triton's fist. "You're angry that Dad doesn't give you things to do. That he doesn't trust you with anything."

"You know nothing," Triton spat with an unconvincing laugh.

"You want him to recognize your power so you're trying to outdo him. What do you think's going to happen? Oceanus'll just give you the ocean and you'll be top-god? I've got the feeling that's not going to go well."

Triton let out a growl and ran at Percy. Water had welled up in the cut in the ground and the black maelstrom glistened in the dark moonlight. It continued to rise as Triton approached until it was lapping at Percy's feet.

Faster than Percy could blink, the god was on top of him and they plunged together into the water before he could even think about swinging Riptide.

Triton dragged him down several feet before releasing him. Percy saw the green double tail reform around him, the godly glow pulsate brilliantly through the pitch, and then it was like he vanished.

The light danced through Percy's eyes, blinding him for the moment as he struggled to force them back into focus.

Something bumped his leg.

He had still managed to hold onto his sword, but he wasn't sure there was much else he could do if he couldn't even see it.

He was pushed from behind but whatever it was had swum away again before he could swing around to face it. He was starting to get angry. He knew it was Triton, he knew he was being messed with, and he didn't like it.

The spots finally began to dissipate from his vision and he glanced cautiously around him.

He was being stalked.

He risked propelling himself forwards, letting his hands investigate the chasm wall. The freshly cut stone was smooth and cold through the water. A shadow just slightly blacker than the rest of the darkness moved to his left, a great heaving creature whose teeth were the only things to reflect light through the void.

Percy raised Riptide and prepared for the charge, but the shark just hung back lazily as if he were waiting for his dinner to strike first. Which he probably was.

It growled, which Percy wasn't quite aware sharks could do, and made a sound that seemed to chill the very water around him.

You're nothing, Jackson, the growl said with Triton's trademark angry overconfidence. I am going to destroy you so that even Father won't want to save you.

"Didn't see that coming," Percy muttered, bracing himself and watching shark-Triton closely. He growled again and bowed his head to charge. Percy sailed out of the way none too soon as Immortal Jaws barreled past, a massive fin clipping his ankle in the process.

He was pushed backwards and into the other wall by the pressure coming off the beast-god, and he realized it was unlikely he would ever be able to dodge every blow Triton could throw (swim?) at him in such a tight space. There was barely room enough for his shark form to swim comfortably, not leaving much room for Percy.

His only option was to get out of the water.

The shark charged again, closer this time and Percy managed to swing Riptide in time, landing a blow to the grey-green flank. Triton yelled but recovered quickly and turned angrily on Percy across the chasm.

He had a little time to scope out how he was going to get out before Triton could get to him, when he caught the glimmer of silver wedged into the rock across from him.

The triple prongs of the royal trident winked at him and disappeared behind the dark mass of shark that passed between them, unaware of the weapon's presence.

An idea came over Percy, but in order for it to have any chance at all he'd have to time it perfectly.

Triton turned on him again and moved to charge. The look on his beady eyed face said he meant to make it the last time. Once he was done, there'd be nothing left of the demigod son of Poseidon except for a shredded orange teeshirt and a broken pen.

The white teeth seemed to grin as they advanced, faster than last time, no chance of Percy slipping away between the giant grey body and the rock.

At the last second, Percy planted his feet on the wall and shot off, sailing past Triton and slamming into the other side. Grabbing for the trident, he heard the crash of shark into stone and wondered briefly how well the already crumbling surface would hold up against the Megalodon body slam. His guess was not very well as he could already see and hear the damage on the pillar as more cracks appeared and a cloud of dust erupted from the spot Triton hit.

The shark wobbled back around to face Percy, dazed by his impact and obviously very confused. His plan had been shattered and he wasn't sure he wanted another go.

He focused his eyes and staggered as much as a shark can possibly stagger in the water as he made out the silhouette of Percy and the trident.

The glow pulsated around him again and Percy prepared for another transformation, but instead, the green double tail reappeared and the merman was back to his normal self. Percy wasn't exactly sure if this was good or not - he'd seen what Triton could do without the disguise of a shark. What he was less sure of was why the other son of Poseidon wasn't doing anything now. Had Percy not known any better, he'd have said the merman looked like he was giving up.

Triton looked up and made eye contact with Percy, his expression unreadable and his fists clenched at his sides as the sea began to shake.

The earth was crumbling and Percy was stuck in the middle.