AN: This is the longest oneshot I've ever written. Of course, it's probably a bit too long to be considered a oneshot, but there was no good place to split this and make it into more than one installment. So it's a oneshot. Inspired by this bit of conversation at the end of TLH:

Clarisse: "Why haven't we ever run across each other on quests?"

Chiron: "Oh, yes. You have, many times. It's always a tragedy, and always the gods do their best to wipe clean the memories of those involved."

And the idea light bulb popped up above my head. What if Percy and Jason had come across each other? This takes place the summer before TLO. (Don't you just love Rick Riordan for giving us fifty-one weeks of unwritten adventures?) Percy POV. A few notes before I begin: 1) No tragedy here. 2) Pyrobolus is NeoLatin (not Classical) for 'bomb.' 3) Sugar high pegasi are possibly the most entertaining things to write ever. Seriously, try it sometime.

Now, enjoy! And please, if you like this enough to favorite it, review? It'd mean a lot. (And I'm greedy.)

Of Encounters and Explosives

Playing paintball with monsters wasn't my idea.

Okay, that probably sounded weird. Maybe I should back up.

Blackjack landed with a quiet thump behind a desolate-looking strip mall. Thankfully, we arrived right on time, midnight, so no mortals saw us. I could only imagine what the Mist would make them see—an enormous bird, or a helicopter maybe.

"Thanks," I muttered as I slid onto the pavement. Pegasi could get pretty ticked off if you didn't acknowledge them after they fly you halfway across the country. A son of Ares forgot once, and months later he still had a hoof-shaped dent on his forehead.

No problemo, boss. The pegasus's head suddenly whipped over to the side, staring at something behind me. I turned and uncapped Riptide, worried that he'd seen a monster or enemy demigods, but then he whinnied excitedly. Hey, can I go check out that candy store over there?

I sighed. Typical.

"Yeah, sure. Just don't eat too much, okay? The last thing I need is a sugar high escape horse."

Blackjack sped off to raid the storeroom, which he was probably going to trash. I made a mental note to leave a few dollars there if I survived.

Shaking my head, I hurried down the street towards the ominous forest that held an old, abandoned warehouse. Kronos didn't pick very unassuming places to store weapons. He might as well have put up a giant sign that said: Warning: this place is dangerous. Do not enter, or an army of terrifying monsters will eat you for breakfast.

Some Demeter campers had discovered the arsenal last month, and naturally Chiron decided to send me to go blow it up. He thought I had experience in pyrotechnics, apparently. I guess a few school buildings make you an expert in the fine art of exploding things.

Right now, ten containers of Greek fire were clanking around in my backpack, next to the emergency drachmas and ambrosia and nectar. I just prayed that the bombs didn't accidentally detonate. Greek fire was the most explosive substance in the world, and one of the most temperamental, too—one wrong move and you go kaboom.

I tried to make my footsteps as silent as possible as I came closer to the warehouse. Back at camp, we'd discussed how to make sure no one heard me, since monsters have much better hearing than demigods (which is really unfair, if you think about it) and we couldn't afford to have me mess up this mission. The plan we'd come up with made me a little nervous. I was going armorless, with only Riptide and the backpack with the super-explosive firebombs and emergency supplies, which really made me feel protected.

When I got near enough to see the armory, I crouched behind a tree and ran over the plan one more time in my head. Get in, kill monsters, plant the explosives, get out. I couldn't help but think that for such a simple strategy, there were so many things that could go wrong.

Something moved only a few yards from where I was hiding. I froze, and then slowly straightened up, taking out my magic ballpoint pen. The whatever-it-was moved closer, and I saw a glow up ahead of me. I uncapped Riptide and it slid out silently, the celestial bronze lighting up the trees around me.

Suddenly, a boy came out from behind a tree, wearing a purple shirt and holding a gold sword. Yeah—a gold sword. It glowed like Riptide, illuminating his pale face and blond hair with a yellowish light. We stared at each other in suspicious surprise.

"Who are you?" he asked after a few moments of tense silence.

"Percy," I said. "Percy Jackson. You?" He frowned when I said my name, but not in the 'oh wait, I'm supposed to kill you' way, which made me a bit less nervous. He didn't look like one of Luke's demigods, but what else would he be doing out here?

"Jason Grace, praetor of the First Legion." I'd never heard of the First Leisure or whatever he was talking about, but his chin lifted a little bit when he said it, so I guess he was proud of being the praetor.

"The what?"

Now, I know what you're probably thinking: Wow, that was really irresponsible of him, stopping to chitchat with a strange demigod in a dark creepy forest during a mission, blah, blah, blah. But the thing was, this kid was definitely not working for Kronos, but he'd also never gone to Camp Half-Blood. I was pretty sure of that. So… what was he talking about?

Jason gave me a funny look, and I was probably giving him an equally confused and suspicious look.

"You've never heard of the Legion?" I shook my head. "What about camp? You've never been to camp?"

"Camp Half-Blood? Of course I've been there. Where did you come from? I didn't think there were any demigods out there that weren't at camp or with Kronos."

"Kronos… you mean Saturn?" he asked.

"Saturn's the Roman name," I said.

"Exactly," he said, looking at me like I was psycho. "No one's called the gods their Greek names for ages."

"Something's not right." I stared at him for a second, trying and failing to figure out what was up. "Who's your godly parent?"

"Jupiter."

I raised my eyebrows. It wasn't often that you saw a Big Three demigod. Especially not ones who talked like they were stuck in the days when togas were all the rage.

"My dad's Poseidon."

"But you're against Saturn, right?"

"Kronos, yeah. You, too?" I asked. Jason nodded. "Well, if we're both fighting kind of the same Titan… even if you call him the wrong name, we might as well work together. I'm guessing you're here to get rid of the warehouse?"

"Ignoring your incorrectness—" I glared, but he just kept talking, "Yeah, I am. A few explosives should do the trick, right?"

I grinned. "I was thinking the same thing. I've got ten jars of Greek fire in here."

"And a pyrobolus should go nicely with that." He adjusted the backpack on his shoulder, and I heard something rattle around in there. "Should we go in together, or have one distract and one plant the explosives?"

I thought for a minute. Even though Jason seemed pretty cool, I didn't exactly trust a guy I'd just met with my life… or with a ton of bombs.

"Together," I decided. "I'd planned to drop them in the center of the building."

"Same," he said. "And then we'll just have to fight our way out, since two bomb-planting demigods aren't exactly inconspicuous."

"Sounds good."

Slowly, we started walking towards the dark warehouse, trying to keep our backpacks from shifting and making noise. Both of our swords were drawn, which made a weird golden-bronze glow in front of us.

I sneaked a glance at him, still wondering who the Hades he was. I'd never heard of a demigod who referred to everything in Roman terms—and what was that Legion he had talked about?

I didn't get the chance to think about it much, though, because just then we got to the door. Which, because we were just that lucky, was locked.

"I got this one," Jason whispered. Reaching into his backpack, he pulled out a small bottle of green liquid.

"Acid?" I asked quietly. He nodded and started pouring it on the door carefully, making sure not to get any on himself. First thing they ever teach you in science class: don't let acid touch you. It's not pretty. With a hiss, the door melted away until there was a big enough hole for someone to fit through. "Nice," I mouthed before slipping in. Jason ducked through right after me, and then we both froze.

Imagine one of those big factories, where they make shoes or potato chips or those tacky souvenir shirts. Then multiply that factory by a hundred and fill it with thousands of deadly celestial bronze weapons and nearly as many monsters. Add all of the chaotic noise that comes with that, too—screeches and rumbling and the clang of metal on metal. That's pretty much what the inside of the warehouse was like.

"Well," Jason muttered. "This'll be fun."

"Oh, definitely. I just love walking into creepy old warehouses full of monsters. Don't you?" I looked out at the creatures hustling around the armory, pushing carts of scrap metal, carrying newly-made weapons, and working at the forges. I saw a few telekhines over in a corner comparing Hello Harpy lunchboxes.

"There are so many. How…?" Jason trailed off.

"We'll just have to try to sneak into the middle, and then fight them off once they notice us." I grimaced. The 'noticing us' part wasn't going to take long—two Big Three demigods in orange and purple shirts were not exactly the most invisible things in a factory full of monsters.

"It's our best bet," Jason said with a quick nod. He shifted the strap of his backpack and gripped the strange gold sword tighter. We started walking towards the middle of the enormous building.

Trying to blend in without being too obviously inconspicuous is a lot harder than it looks in the movies. We couldn't just go in secret agent style, rolling across the floor and taking out monsters as we went. They would have noticed right away, and it would have also made me feel pretty stupid when they did. So instead we tried to walk casually, not looking any of the monsters in the eye or going too quickly.

It didn't work very well. Halfway to the middle, a harpy stopped and sniffed.

"Do you smell that?" she asked the monster next to her – some kind of half human, half insect. The creature wrinkled its nose.

"Smells like demigod… like the sea." Jason shot me a frantic glance, but before we could get away, the harpy turned and looked straight at me.

"Go!" I whispered to Jason, shoving my backpack into his startled hands. And then I did something that was really pretty stupid, even for me. I tackled the harpy.

She screeched and threw the swords she was carrying up in the air. Some of them landed on me, and I found out that they were fresh out of the forge—white hot. I scrambled to my feet, but not before the harpy got in a nasty bite to my hand. Her bug friend tried to lunge at me, but I swung Riptide and she turned to dust. The harpy slashed at my shoulder, and I sliced off her head and she vanished with a wail that grated on my ears.

I looked up to see every single monster in the warehouse staring at me. Two down, a few hundred more to go.

"Get him!" one of the telekhines yelled. They all surged forward with weapons drawn and claws extended with the intent of slicing me to ribbons.

War is just so much fun, isn't it?

My mind went on autopilot. I sliced one of the first monsters with Riptide and simultaneously kicked a dracaena in the gut. An entire row of strange creatures that I didn't take the time to name disintegrated with a wide slash. A hellhound scraped at my head, and I stabbed it quickly before it could do too much damage. I dodged a clawed hand and ducked to take out a telekhine from behind. A harpy's talons tore at my back, but I twisted and somehow managed to spear her on another monster's weapon. In minutes I was coated in monster dust.

As I fought, I saw a flash of a purple shirt in the center of the warehouse. None of the monsters had noticed Jason yet.

I hopped up on top of one of the platforms to get better leverage. From what I could see, there were about a hundred monsters left. One of them slashed at my legs and I kicked it in the head. I sliced through another line of dracaena who were climbing up the side of the platform, but more followed them, surging over the edge like in a horror movie.

I was completely surrounded. Well, this might be it, I thought as I stabbed a harpy.

Suddenly, I heard a popping noise coming from the back of the crowd of monsters, and a whoop of "Yes!" The monsters howled and screamed and hissed as bullets hit them and made them vanish. The survivors started running, tripping over each other as they tried to get away from the shotgun-wielding demigod in purple.

"Nice!" I called. Jason just grinned and tossed me a gun just like his. I'd never used one before, but I'd played enough video games to know how. A spray of multicolored bullets peppered the monsters, and I watched as small splashes of paint exploded.

"We should get out while they're distracted," Jason yelled over the sound of gunfire. I nodded and made some of the rusty old pipes burst for effect. Then we sprinted for all we were worth.

"Paintball guns?" I asked, panting, as we ran to the stakeout spot.

"Must've been laced with something," he gasped.

The distance seemed much longer than it had when we were sneaking across, but somehow we made it to the shelter of the forest. "The detonators," I said. "Do you have them?"

"Yeah," Jason said, handing me the celestial bronze one. "They're the only thing I grabbed from the backpacks, though. It would've slowed us down."

"No problem. These are the most important."

Jason looked at me and winced. "You definitely could've used that ambrosia and nectar."

I looked down and saw that I was pretty much covered in blood, monster dust, and paint. My clothes were ripped to shreds. "I've had worse," I told him. "Detonate on the count of three, okay?"

He nodded, flipping a switch on his device.

"One… two…" I glanced back over my shoulder at the building, where I saw monsters starting to come toward us. "Three!"

If you've never heard or felt an explosion in person, you're lucky. The sound was like a jet plane taking off in the middle of a fireworks show, and the massive shockwave knocked us both off our feet. Even in our distant position, heat seared our skin. We sat on the forest floor in shock, watching the green and red flames consume the armory.

"I think the explosives worked," I said breathlessly.

"Oh, gee," Jason muttered. "You think?"

I started to stand, using one of the trees for support. "We should get moving."

"Yeah," he agreed, pulling himself up. He stared at me. "So, is this where we split up?" I nodded.

"I think so. Unless you want to come back to camp… we could use someone like you."

"I can't," he said. "Lupa will be waiting for me." Seeing my confused expression, he added, "Our commander. Camp director, you could call her. She's a wolf."

"A wolf is your camp director." I grinned. "Cool. Ours is a centaur. Well, actually, he's the activities director. Our camp director is a drunken god on probation." Jason looked a little alarmed at that, but I just said, "Long story."

"Well. Um. Nice meeting you, Percy Jackson." He stuck out his hand, and I shook it.

"You too. Maybe we can Iris-message sometime," I said. "It'd be good to have two camps working together, with the war and all."

He looked a little confused, but he nodded anyway. "Yeah. So, um…"

"Yeah." After giving each other one last glance, we both walked away in different directions.

And that was how the most awkward, confusing mission I've ever done ended.

Once I got closer to the small town, I whistled for Blackjack, hoping that he'd listened to me and been moderate with the sugar.

I was wrong, of course.

It took five whole minutes to get him to stop doing flips in midair, and then another five while I waited for him to calm down enough for me to clamber on top of him. He kept up a constant stream of half-intelligible nonsense.

…And there was licorice—piles and piles of licorice!—and candy apples and jelly beans and chocolate! Lots of chocolate. And these giant blue lollipops—hey, boss, you've never told me why you like blue candy so much. I mean, blue is Zeus's color, right? Poseidon's more of a green guy. Like, sea foam green or something. Turquoise. Teal. Hey, do you think…

I seriously considered just walking all the way back, but I figured once he came off his sugar high, Blackjack wouldn't be too happy about that, plus I was pretty tired.

The uglies reeeeally got you this time, didn't they boss? he said with a whinny.

"Mhm. Now how about we get back to camp? There'll be apples, and you can take a nice, long nap…"

Blackjack snorted. Nap? I don't need to sleep! I could fly around the world at top speed ten times and be perfectly—

"Oh, trust me," I muttered. "You'll want to sleep later. C'mon, let's get going while you're still hyper."

Blackjack crashed when we passed over New Jersey. Metaphorically, I mean, although we came pretty close to literally crashing the more tired he got.

"Hey," I said. "It's only a little bit longer. You can make it."

He yawned, which I didn't even know was possible for horses. Yeah, boss. I can do it no pr… He yawned again. Sugar cubes. I'm going to have some sugar cubes when we get back.

"Sounds like a great idea," I told him, fighting off a yawn of my own. Whoever said those things are contagious was dead on.

Thankfully it was still dark, which meant that the mortals couldn't see when Blackjack began stumbling at random intervals, causing us to plummet toward the earth until he jolted awake again.

No, really. It was great.

Finally, after hours of flying, the coastline of Camp Half-Blood came into view, becoming increasingly visible thanks to the small rays of sun beginning to peek over the horizon. It didn't look like anybody was awake yet, except for the unlucky people who'd gotten the early morning shift of guard duty.

Just then, Blackjack hit the last stage of his sugar crash: complete and utter exhaustion, quickly followed by coma-like sleep. I could already hear his mind getting less coherent by the second.

"Blackjack. You have to stay awake for just a few more minutes, okay?"

Yeah… he said back, Just a… Sleepy… I want sugar cubes.

"If you stay awake, I'll give you all the sugar cubes you want," I promised him. I looked down and saw the beach getting closer. Only half a mile left. "And once you're awake again, you can have a day off, and…" I kept talking to him, hoping that the noise would help.

"Just a little bit longer. There's just a few feet till we land. And then you can sleep."

We began dropping faster.

"Blackjack, you need to slow down. We're coming in too fast."

No answer.

"Blackjack!" I glanced to the side and saw that his wings were drooped. He was asleep. And we were about to crash land right next to the lake. "Blackjack! Wake up!"

Not waiting for a reply, I slid off his back and landed on the sand, my ankle twisting painfully under me. I ignored it and concentrated on the waves. One of them, thank the gods, rose up and grabbed the falling pegasus around the middle, slowing him down and then setting him gently on the sand.

I breathed out a shaky sigh of relief and started to walk towards him, but apparently my body had other ideas. As soon as I took a single step, I collapsed, and everything went black.

"Is he alive?"

"I dunno. That was a nasty fall…"

"Wonder what happened."

The sound of voices woke me up, which I really didn't appreciate. I was sore. I wanted to stay right where I was, lying on my side in the soft sand. Sand… Something tugged at my memory. We had landed on the sand… by the lake… Blackjack! I tried to move, to see if he was okay, but I was too exhausted.

"Go get Chiron," the first voice was saying. I heard someone running, the footsteps going farther away. And then a few seconds later, the sound of a conch horn from nearby. I guessed it was from the first person.

"Percy," they said. I think it was Connor. He shook my shoulder. "Hey, wake up."

I heard the sound of more footsteps coming closer. Someone ran up and kneeled next to me, which sent a spray of sand in my face. I squeezed my eyes shut tighter.

"What happened?" a girl's tense voice asked. Annabeth.

"They crash landed," Connor explained. "Blackjack just, like, stopped flying, and then Percy jumped off and made the lake catch Blackjack. And then he collapsed." He paused for a second and then added, "I think the rest was from the monsters."

I heard Annabeth wince. She grabbed my shoulder and accidentally pulled at one of the gashes from gods-know-what monster. I groaned, and she pulled her hand back immediately.

"Sorry, Percy," she said.

I slowly blinked my eyes open. They felt like cement.

"Well, at least we know he's alive," Connor muttered.

I looked around. Connor and Annabeth were kneeling on the sand next to me. A couple other campers were standing a few feet away, next to an enormous black lump.

"Blackjack?" I asked.

"He's okay," Annabeth confirmed. "Unconscious, but fine. You, on the other hand, look like you got trampled."

"Not too far from the truth," I grumbled, sitting up slowly. "There were more than we thought. I'm talking hundreds."

Her eyes widened. "So did you…"

"Yeah. Whole thing exploded. I don't think any of them survived." She nodded and asked the campers behind her if they had any ambrosia or nectar. Someone handed her a slightly crushed square of ambrosia, which she promptly shoved into my mouth.

Once I managed to swallow it, I said, "I can eat on my own, you know."

"Oh, good boy," she said sarcastically. "Can you say your ABC's too?" Before I could come up with some kind of witty comeback, Chiron cantered up.

"Percy," he said. "How did it go?"

"All the monsters are in Tartarus, and the armory is a smoldering wreck. So pretty good." I stood using Annabeth's shoulder for support. My ankle felt fine, which was good. I looked up at Chiron. "I need to talk to you, though."

He raised an eyebrow curiously. "About what?"

Something told me I shouldn't talk about Jason and his other camp in front of everyone. "Um…"

"I see." Chiron nodded like he completely understood. "Follow me." He turned and started walking up towards the Big House. Mouthing I'll tell you later to Annabeth, I jogged after him, only limping a little bit.

I sat down heavily on the old leather couch.

"So," Chiron began. "What did you see?"

I knew better than to ask how he knew. I took a deep breath. "When I was there waiting, I bumped into another demigod, named Jason. He didn't work for Kronos, but I'd never seen him at camp before…" I explained the way Jason talked about everything in Roman terms, how we worked together to explode the armory, and what he'd mentioned about another camp out west.

By the time I finished talking Chiron's face was so pale I thought he might pass out. He started pacing, his hooves making a rhythmic clip-clop sound on the wooden floor. "I knew this would happen," he sighed, running a hand through his beard anxiously. "It always does."

"Um, sorry, but… what always happens?"

He stopped pacing and looked at me mournfully. "Percy, this is very, very dangerous territory. I'm surprised you and Jason didn't kill each other, actually."

"What do you mean?" I asked, unnerved.

He didn't answer.

"Chiron…" I hesitated. "There are other demigods, aren't there? Like, not Greek ones. Romans."

He was silent for a long time before answering, "Yes. You're right." I looked at him in shock.

"So why are we separate? Wouldn't—"

"Over the last several millennia, Greek and Roman demigods have clashed consistently and violently," he explained. "Some of the bloodiest conflicts in the history of mankind—the Trojan War, the American Civil War—those were between the two kinds of demigods. It's nearly impossible for Greeks and Romans to cooperate for too long before they begin fighting."

"If we've fought so much in the past… how come we don't know about them now?"

Chiron winced. "After the Civil War, the gods decided that the two sides were simply too volatile. They wiped the memories of everyone involved, stuck a continent in between the two camps, and declared that they should never again know of the other's existence."

I let that sink in.

"And speaking of wiping memories," he began.

I jumped up in shock once I realized what he was saying. "No. No way."

He looked at me sadly. "It's the only way, Percy. No one is allowed to know."

"But it doesn't have to be like that," I protested. "Jason and I worked together just fine. Is it so far-fetched that the two camps can too?"

"I'm sorry." Chiron snapped his fingers, and everything went black for the second time that day.

When I woke up, I felt like a Cyclops had sat on my head. I was pretty sure that my wounds were healed, but I was still sore.

"Ah, Percy. You're awake." Chiron came into the infirmary, ducking his head as he passed through the doorway.

"What… what happened?" I asked groggily.

"When you got back from your mission, you said you needed to talk to me," he said, face deadly serious. "But you collapsed before you said anything."

My eyebrows knit together as he spoke. I remembered all of that happening… but it was strangely fuzzy.

"Do you remember what you wanted to tell me?" Chiron prodded.

"I think…" I frowned. "I don't remember exactly, but I think it was something about monsters."

He looked strangely relieved. "Well, if you remember…"

"Yeah." He left the room quickly, leaving me trying to figure out what it was I'd forgotten. The only memory that came to me was of something…

Something gold.