Chapter Text
The night air was full of salt and gunpowder.
The Winchesters were working a case in Salem, Massachusetts where people were being torn apart by the ocean leaving the cops stumped with no identifiable leads. The only helpful evidence they gathered came from a witness who swore a beast came from the water and killed them. Of course, this witness was the only one of 50 or so bystanders who saw anything tangible beyond normal accidents.
After a long and frustrating day of dead ends, the Winchesters waited until night fall to scope out the industrial building where most of the victims had turned up by. Several of the deceased worked at the canning facility and the building had been thoroughly searched by the police with no clues as to a motive.
Dean pulled the Impala up to the side entrance and shared a look with Sam before turning off the engine and opening the trunk. A quick debate and the brothers decide to go with the usual and cover their bases; shotguns loaded with salt, silver blades, and holy water.
As they crept into the building with shotguns in hand, they heard the clanking of chains followed by a slithering sound dragging across the concrete floor toward the east side of the building. Nodding at one another Dean advanced left, tracking the sounds.
Dean paused in his steps as a sudden movement flashed in a doorway ahead of him. The thing - whatever it was - was fast, too fast to be human. Well, Dean thought to himself, hope this thing likes salt rounds.
Raising his shotgun, Dean squinted into the darkness where the creature – slippery from the sound of it – had vanished dragging a trail of questionable dark liquid across the cracked asphalt.
“Sam, you see where it went?” Dean barked, quickly looking around to see where his brother had gone. He could taste the air in the cannery; damp, briny, like a pier at low tide.
He heard a shotgun fire and a hissing sound after impact and Dean swiveled toward the sound.
“Sammy!” Dean yelled.
“I hit it! I think?” Sam replied.
“You think?” Dean said, walking over to where Sam’s voice had come from.
“Well, the shell hit it, but it didn’t seem to do any damage.” Sam said as Dean approached. “The damn thing just took off that way.” Sam pointed in the direction of the docks. “Whatever it is, it’s fast. And it didn’t bleed when I hit it.”
Dean gritted his teeth. Great. Another freak of the week immune to their usual bag of tricks. He hated cases like this – nothing in the lore, no reaction to salt, just a trail of slime and a growing body count.
He was about to suggest regrouping when the temperature dropped. The air became heavy, like a wet cold blanket. Dean turned sharply, heart thudding and saw a figure stepping out of the shadows.
The guy was young, maybe late twenties. He had messy black hair, sea-green eyes that were so vivid the moonlight made them look like they were glowing. He was wearing jeans, a battered leather jacket and was holding – was that a sword?
Dean immediately raised his shotgun. The guy didn’t even flinch. Instead he said, casually, “You’re gonna want to duck.”
Dean didn’t move fast enough. Behind him, the monster – a serpent-like thing, scales slick and black – lunged from the shadows. Before he could react, the new stranger moved faster than Dean could fathom, bronze blade flashing, and slashed at the creature. As if that wasn’t enough, the ground split open at his feet, a surge of water blasting up from the cracks like a geyser.
The monster was slammed by the flood and let out a horrible screech, hissing as the water invaded the new wound in its side and was thrown back into the wall behind it.
Dean stumbled, gaping. “What the—”
Sam yanked him down just before a second surge crashed overhead.
By the time Dean rolled back up onto one knee, shotgun raised, the creature was dead, cleanly decapitated by the stranger’s blade. The ground steamed where saltwater hissed against the bloodstained asphalt.
The stranger turned, planting his sword in the ground like it was nothing. "You're welcome," he said, grinning.
Dean and Sam exchanged a long look.
Then Dean said, very slowly, "You wanna tell us what the hell you are?"
The stranger laughed, brushing damp hair off his forehead. "Name’s Percy," he said. "And what I am is complicated."
Dean tightened his grip on the shotgun.
"Yeah," Percy added, a little more serious now. His eyes -- so damn green — flickered between them, weighing, measuring. "But I think we’re on the same side."
Sam straightened, ever the diplomat. "You hunt?"
Percy shrugged one shoulder. "When I have to. When monsters cross the line."
Dean’s brain was still catching up. Normal humans didn't pull water out of nowhere. Normal humans didn't slice down goddamn sea monsters like they were Tuesday's lunch.
“You’re not a hunter,” Dean said flatly.
“Nope,” Percy agreed easily. “Not the kind you’re used to.”
“And you’re not human,” Dean pressed, shotgun still steady.
Percy gave a small sad smile. “Not as much as I used to be.”
Dean stared at him.
Sam exhaled slowly. “Maybe we should talk somewhere less... exposed.”
Dean wanted to protest. This guy was weird, and Dean didn’t like weird he couldn't explain. But the truth was, Percy had saved their asses. And somehow, Dean didn’t think they were done with whatever the hell tonight had stirred up. "Fine," Dean muttered. He jerked his head toward the Impala. "You’re riding with us."
Percy casually touched something to the tip of his sword, and it shrank into what looked like a cheap pen. "Shotgun."
Dean blinked at the action and then growled. "No way in hell."
Percy just smirked.
When the reached the car Dean glared at Percy while Sam shrugged and sat in the front passenger seat. Percy took a long look at the car, traced his finger across the side and then slid into the back seat with an air of nonchalance.
“Nice car.” Percy said. Dean grunted. Sam gave Dean the side-eye.
The trip back to the motel was awkward. The Impala rumbled down the empty highway, headlights cutting a path through the night. Dean gripped the steering wheel a little too tightly, eyes flicking to the rearview mirror every few seconds. Percy sat sprawled in the backseat like he owned the damn car, tapping his fingers on his knee in an unidentifiable rhythm.
Dean didn’t trust him. Not even a little bit.
He was also ignoring the part of his brain that had noticed the way the guy’s jacket clung to broad shoulders, the way the visible bruises and scars on the guy’s hands and face spoke of years of fighting, the way his cheekbones and jawline looked like they came from a famous sculpture…
Dean subtly shook his head to clear his train of thought.
Sam, predictably, was already in full research mode, typing rapidly on his laptop in the passenger seat.
“So,” Dean said finally, voice sharp, “you gonna tell us what the hell that thing was? Or do we get to keep playing Guess Who all night?”
Percy snorted. “It was a ketos. Greek sea monster. Old-school nasty.”
Dean blinked. "Greek?"
"Yeah. One of the minor ones. The gods don't exactly keep their old pets on a tight leash anymore."
Dean shot a look at Sam, who frowned thoughtfully. "There’s no record of anything like that showing up around here," Sam said. "No lore matches. No previous sightings."
Percy leaned forward, resting his arms on the back of the front seat like they were old friends. Dean realized that Percy seemed completely dry even though he could have sworn he was soaked from the aftermath at the cannery. At least he wouldn’t mess up the upholstery?
Fidgeting with that same unremarkable pen from earlier Percy replied, dragging Dean back to the current conversation “that’s ‘cause normally creatures like that stay in my world. The Greek world. Olympus keeps ‘em bottled up but recently…” He hesitated, and for the first time, a shadow crossed his face as the easy-going façade seemed to slip. “Somethings happening. The old boundaries aren’t holding like they used to.”
Ignoring the thousand questions that had just been inspired by that latest statement, Dean decided to respond with, “Is your sword a pen?”
Percy lit up and went to explain but Sam held up a hand. “Wait,” Sam said, cautious. “Olympus? As in the actual Greek gods?”
Percy gave him a look. “You believe in angels, demons, and everything else that goes bump in the night, but this is where you draw the line?”
Sam opened his mouth, then closed it, looking sheepish.
Dean had refocused on what Percy had said and was stuck on something. “You said ‘my world’ and that ‘the gods don’t keep their pets on a leash anymore.’” Dean narrowed his eyes. “Sounds like you know them.”
Percy’s jaw tightened — just for a second — and Dean didn’t miss it.
"Let's just say," Percy said carefully, "I have some... experience with their particular brand of family drama."
Dean's gut twisted. Family drama. Yeah. He knew a thing or two about that.
"You a god or something?" Dean asked, half-mocking.
Percy barked a laugh. "Hell no. I'd be taller."
Sam smothered a laugh behind his hand.
Dean grunted, refocusing on the road. He hated mysteries. Especially mysteries with smart mouths and swords and cheekbones that could cut glass…
(He was not thinking about the cheekbones.)
They pulled into the cheap motel parking lot ten minutes later. The grand palace of flickering neon signs and questionable stains on the walls.
Dean cut the engine and they all piled out.
They pulled into a cheap motel half an hour later — the kind with flickering neon signs and questionable stains on the walls. Dean killed the engine and they all piled out. Sam grabbed his laptop and a handful of lore books from the trunk, heading toward the room with a focused look. Dean hung back, watching Percy sling a battered backpack over one shoulder, still fidgeting with his sword-pen thingy.
"You always pack a blade to a gunfight?" Dean muttered.
Percy shrugged. "You ever try shooting a hydra?"
Dean opened his mouth — then closed it. Fair point.
Inside, the motel room smelled like old cigarettes and cleaning fluid. Sam dumped his research onto one of the double beds, already setting up. Percy dropped onto the other bed without asking, arms stretched behind his head. Dean glared at him. Percy just grinned lazily, like he knew exactly how far he could push without getting punched.
"You gonna explain how you pulled a water cannon outta the ground back there?" Dean demanded.
Percy tilted his head. “You gonna try to kill me for not being human?”
“Well see,” Dean snapped.
Percy sighed. “Are you familiar with the Greek gods from the stories?”
Sam perked up, “like Zeus, Hera, Aphrodite—”
Percy shushed him. “Names have power.” He replied ominously. “But yes those gods.” Sam nodded and Dean looked between Percy and Sam before nodding as well. Percy continued, “Well you know how the heroes in those stories were descended from the gods?”
“Like demigods?” Sam asked. Percy nodded. “We’ve met one or too but not Greek.” Percy quirked his head curiously at that but seemed to refocus.
“Well, you’ve just met another one. Greek one that is.” Percy said. Dean just stared at him. Sam looked like his questions had sprouted questions.
“You’re the son of a god? Like… literally?” Sam asked.
“Literally.”
Dean scrubbed a hand down his day-old stubble. “Jesus Christ.”
Percy smirked. “Wrong pantheon.” Dean snorted. “Right.”
Sam was already flipping open a book. "This would explain the ketos showing up here," he said, half to himself. "If the Greek pantheon is bleeding into our world, that means new monsters, new rules..."
"New headaches," Dean muttered.
Percy sat up, a little more serious now. "Look. I’m not here to screw with you. I hunt monsters, too. Same end goal, different... heritage."
Dean narrowed his eyes. "Why now? Why show up here? Does this have to do with your…” Dean waved his hands, “parentage?” Percy's face shuttered for a moment. Dean caught it — a flash of something heavy. Fear. Responsibility. Something Dean knew all too well.
“This creature in particular has ties to my parentage, I guess you could say. Honestly it just happened to be water-related which worked out for my powers. I’m mostly here because if the walls between worlds are breaking, if the mist is getting weaker, you’re gonna need my help.” Percy had slowly gotten quieter.
Sam jumped in, “So you have water-related powers?” Percy nodded. “And the ground broke.” Percy nodded again. “And is your dad a god?” Percy nodded a third time. “Poseidon!” Sam shouted like ‘Eureka!’. Percy smirked a bit and nodded again.
“You would give the Athena kids a run for their money. It took them a week to put it together when I first showed up at camp.” Percy chuckled.
Sam looked like he had just discovered a new planet. “There’s a camp full of you—full of demigods?” Percy nodded, looking a bit somber Dean noticed.
“There aren’t as many of us as there used to be.” Percy murmured, looking at a spot on the ground. Dean wondered about the story there but picked up that further questioning on that topic might be unwelcome.
Percy looked up as Dean spoke, “so you’re some kind of water bender? Like something from Avatar? What, can you surf really well?” Percy snorted and it seemed like the right way to break the tension.
“I’ve honestly never tried surfing sadly enough. But I can walk on water.” Percy added.
“Jesus Christ” Dean muttered.
“Yes.” Percy said solemnly.
Dean turned to Sam. “Should we call Cas? He might know more about this.”
“Probably.” Sam said. “It’s your ‘profound bond’ though so you probably should.” Sam rolled his eyes. Percy looked between them and mouthed ‘Cas?’
Dean turned away and closed his eyes. “Cas. Castiel, we found this guy who’s apparently Hercules’ cousin or something--” Percy groaned. “Dude, I hate that guy.” Dean ignored him and continued, “and we need to figure out another world-breaking situation so if you’re not busy with stunt angels #1 and #2 could you get your feathery ass down here to figure this out?” Dean opened one eye, looked around, then sighed and turned back to Percy and Sam.
“Now what?” Percy asked.
“Now we wait.” Dean said and plopped down on a chair at the meager motel table.
The motel room was filled with the soft clatter of laptop keys and the low hum of tension.
Sam sat cross-legged on his bed, flipping through a lore book with one hand while typing into his laptop with the other. Dean leaned against headboard, arms crossed tight, watching Percy like he might sprout a second head if they looked away too long. And Percy, infuriatingly casual, had propped himself up on one elbow on the second bed, scrolling through something on his battered phone.
Dean hated how normal he looked. Like he wasn't some god-spawned miracle kid who could summon storms and kill monsters with a wave of his hand.
"So what’s the plan, Aqua Boy?" Dean muttered finally.
Percy didn’t even look up. "Tracking the next leak."
Sam perked up. "Leak?"
Percy nodded. "Creatures from the Greek pantheon don’t just pop up randomly around mortals. There are... cracks. Rips. Tiny faults between their world and yours. If something opened a hole big enough to let a ketos through, it won’t be the last."
Dean's jaw clenched. "You saying there's more on the way?"
Percy tossed his phone onto the bed, sitting up. His face, for the first time, was deadly serious.
"No. I'm saying there's already something bigger coming. The ketos was just the advance guard."
A heavy silence fell.
Sam closed his laptop slowly. "Any idea what it might be?"
Percy hesitated — just long enough that Dean caught it.
"There are old monsters," Percy said finally. "Older than the gods themselves. If one of those wakes up..." He trailed off, grim. "You're gonna need more than rock salt."
Dean straightened. "You're not scaring us off, kid."
Percy's mouth quirked — not quite a smile. "Didn’t think I was."
Sam cleared his throat. "There’s an abandoned dockyard about thirty miles from here. Cops found bodies washed up — weird injuries, no cause of death. Could be another breach."
Dean grunted. "Then that's where we're headed."