Author's Note: Hey! This is my first(and hopefully not last) non-oneshot story. Gravity Falls and Danny Phantom are two shows I am illogically devoted to, and I was prompted to write a crossover for it! Hopefully things will make enough sense, but just so it's clear, Phantom Planet didn't happen, and this is the summer after Danny's sophomore year. As for the twins, this is kind of a 'between the canon episodes' sort of thing, so Bill Cipher isn't a factor yet. Danny just had a whole ton of responsibilities dumped on him by Clockwork, one of which being that he needs to make sure that the other newbs are doing their jobs right. Danny, being a little wiser after two years of ghost fighting, goes by Phantom in his ghost form now, because not everyone is as oblivious as the people of Amity Park. Anyhow! I hope you enjoy, and I'll try to keep updating as fast as possible!

(As a side note, the relationships in this probably won't be playing a major role, just Sam and Danny, and a tiny pinch of Dani and Valerie thrown in, but nothing that really affects the story line.)

Enjoy!

Edit: The cover image is by thecottonproject on tumblr!

Chapter 1

An old rusty taxi creaked to a stop, the door squeaking as it swung open. The greasy-haired man sitting behind the wheel peered at the sign signifying the border to the small town, dubiously.

"Are you sure this is where you meant me to go? Seems kind of run down."

"Yeah, don't worry about it."

A lanky teen with messy black hair and startlingly blue eyes slowly unfolded himself out of the backseat and out of the open door, sliding around the back and opening the trunk. With no obvious strain, he pulled out a heavy looking backpack, sliding it on with practiced ease. He came back around the side of the car where the man waited, an elbow hanging haphazardly out a window. The boy shoved his door closed with a hip and fished in his pocket for his wallet, pulling out the approximate amount of money and pressing it into the mans hand with a mutter to keep the change. The middle-aged man took one last wary glance at the sign before shaking his head and stamping on the gas, leaving a cloud of dust to billow around the teenager.

Danny Fenton sighed and shook his hair to get the grime out, inspecting the sign as well. Parts of it were newly painted on a different shade of wood, in a suspiciously hole shaped patch. He wondered how exactly somebody had managed to drive a hole through a sign that high up, before dismissing it and turning away. However it happened, Gravity Falls would probably shape up to be just as weird as where he had come from. He twitched involuntarily as a sharp blast of music emitted from his pocket, slicing through the silence. Casting a wary glance at the nearby forest, he pulled his Fenton Phones out of his pocket, looped them around his ears, and hit the side of them.

"Hello?"

He winced as a cacophany of voices all inturrupted each other on the other end.

"Yeah, okay guys, calm down. I'm fine, don't worry."

The shouting narrowed into murmurs, and a familiar sarcastic female voice took over.

"Where are you Danny?"

"This little town in Oregon. Kind of reminds me of Amity Park, actually."

"And let me guess, this is Clockwork's doing?"

"You got me there, Sam. Apparently, defeating a huge tyrant to protect your town from imminent destruction comes with some strings attached. Sorry I didn't tell you earlier, but Clockwork didn't really give me much time, if you know what I mean."

He chuckled as there were multiple groans on the other end, before continuing.

"Yeah so basically, I got some responsibilities and stuff as Clockwork's apprentice and so yeah."

There was a suspicious silence on the other end.

"Danny, what aren't you telling us?"

Danny shrugged noncommitally, before remembering he was talking to them over the phone, and scratched the back of his neck.

"Nothing important, but anyways I have to check up on places with high supernatural influence and help out whoever's in a position of authority slash knowledge on it. Good authority slash knowledge, I mean."

"... How do you know somebody will be in charge?"

Danny smiled a bit; successful subject change.

"Clockwork said there's always somebody who keeps the balance, it's just my job to check up on them from time to time, considering... I have a lot of experience in the immortal realm and stuff, y'know."

Grimacing slightly at his slip-up, he quickly changed the subject.

"Anyways, how's stuff going over there? Dani and Val doing ok on their own?"

There was a brief burst of static on the other end, and then a new voice answered, one that was clogged up with all kinds of different accents from when the person had been traveling the globe.

"Yeah, yeah you big mother hen, I'm doing great, and so's Val. She's been asking questions though, and I think she might realize soon. Right now she's been stuck on thinking Phantom's linked to Fenton and has to follow whereever he goes, but it probably won't be long until she realizes the truth."

Danny paused, both Dani's words and tone striking a chord with him. The words were expected, but that familiar wistful tone...

"... Well I guess it's really up to her about how she takes it. But if she starts beating herself up about it in front of you, let her know that I don't blame her for anything, totally forgiven, water under the bridge."

Sam muttered something uncomplimentary and Dani covered the phone and said something venomous back. There were a few more tense comments while Danny blinked slowly, coming to a conclusion.

"Sorry about that, I'm back."

"Hey, do you like Val?"

There was a sputtering sound on the other end, and then Sam's distinct voice.

"Well if the Clueless One himself noticed your shoddily hid affections, Valerie definitley has."

There were identical protests from the cousins, and Tucker's laughter in the background. Danny smiled a bit, missing them even though he'd only been gone a day.

"Hey, what about Mom and Dad, how're they?"

Dani seemed grateful for the subject change, sighing a bit into the phone.

"They're as clueless as you can be. I've been avoiding them in human form just in case. They don't really bother me in ghost form, just ask a few questions about where Phantom is and why I look like him. I use really vague and mysterious answers, which is fun! Of course, Val- well, the Red Huntress- vouching for me also helps a bit."

There was that wistful tone again, Danny bit his tongue to keep from laughing and started walking down the path to the town.

"And they still think I'm at camp?"

"Yup. Where're you going to live there anyways?"

"There's a tourist trap type of place farther into the town, and it offers boarding for a rather extravagant price and babysitting, but whatever, it works fine."

"Really, a tourist trap? The heck kinda town is this?"

"An odd one. I can already feel the paranormal energy, and I'm not even in the town yet. Though, it seems to be coming from the creepy forest rather than the town itself."

Suddenly there was some rustling and muttering, and Tucker's voice came through the earphones.

"Wait, did you say babysitting?"

Though the tips of his ears turned a bit red, he nodded out of habit as he spoke.

"Yeah, I've gotta watch after these two preteens. They apparently get into a lot of trouble on their own, so their great uncle told me that I could stay if I went with them whereever they get off to and make sure they don't die or anything."

"I hope they at least have wifi or something there."

Danny rolled his ice blue eyes.

"I think I'd be more happy with them not finding out my secret."

"Wifi though."

There was a thud and a yelp on the other end and suddenly Sam had the phone again.

"Yeah Danny, try to keep Phantom on the down-low here, after all this place probably isn't used to stuff like Amity Park is."

"Alright, Sam, I will. I gotta go, wouldn't want to seem more unusual to the locals. Tell Jazz to call me sometime, I gotta talk to her."

"Got it. Bye Danny. Be careful."

"I'll try my best."

Danny tried and failed to not blush as the other two people made kissing noises in the background. Those two had been smug as hell after Sam and Danny finally got together, after an incident with a ghost-proofed closet and the first day of April. Two consecutive thumps and yelps were heard, and Danny grinned. They'd never learn.

"Thanks, Sam. Alright, bye guys!"

A chorus of byes rang through the phone before the call went dead. Danny sighed and stuffed the Fenton Phones into his pockets, and brushed a hand through his hair.

Somehow, he didn't think his trip would be that simple.

"KIDS! GET DOWN HERE!"

Dipper winced at his gruncle's terrible sense of volume and sat up on his bed. He had been trying to read some of the more illegible entries in the journal, to his growing frustration. The short brown-haired boy closed the leather-bound book and slid it into his vest, hopping off his messy bed and heading down to where Stan was waiting impatiently. Hopefully this wouldn't be another irritating chore, Dipper thought grumpily as he made his way downstairs. Stan was standing in the living room in front of the turned-off TV, tapping his foot. Mabel was already there, having been playing with Waddles down in the shop or something beforehand. Stan looked slightly appeased, like he had been informed of something pleasing. Dipper hoped that he wouldn't have to dress up for an exhibit again. That had been the epitome of embarrassing. He turned his attention to his fez-wearing great uncle, still fiddling with his vest.

"Kids, we have a guest staying here for a while."

Mabel and Dipper were both instantly curious and a bit apprehensive (on Dipper's part).

"What? Where are they going to stay? All the rooms are full."

"He's taking the couch."

"Does he know he's taking the couch?"

"Nope."

Mabel frowned a little, confused, and Dipper resisted the urge to roll his eyes. Stan continued.

"The point here is that he's paying to stay here and it's your job to make sure he doesn't get into anything dangerous while he's here. He's got some crazy parents, so he's probably a bit whacked as well. I told him to keep an eye on you two, so he's more or less your responsibility for the two weeks he's staying here. Make sure he doesn't steal anything."

Mabel seemed fairly enthusiastic about a new face, but Dipper was wary.

"How old is he?"

"Sixteen. Now clean up a bit, I don't want him trying to leave without paying or something because the house is gross."

The twins groaned and reluctantly did as he asked, shuffling trash away and making the house look at least a little presentable. As they did, they talked.

"Mabel, how am I supposed to investigate the stuff in the journal with this guy around?"

"Just bring him with us, of course."

"What?! Mabel, we can't tell him about the book!"

"I didn't say that, Dipping Sauce, he can just tag along and not know!"

"Don't you think maybe he'll notice all the weird stuff going on?"

"Like the rest of the town notices? Plus his parents are apparently whack-o, he might just dismiss it as a prank or something."

"Fair point."

"Plus, if he does think something weird is going on, I can persuade him not to tell with stickers!"

Dipper snorted at his sister's antics as she pulled a sheet of stickers out of her sweater and waved them around. Waddles snuffled from his spot on the floor. The shop bell rang and Dipper heaved himself off the couch, where he'd taken refuge from cleaning, and walked through the push door into the shop, Mabel following his lead. A few customers were looking skeptically at a basket of broken glass and the ginger cashier was dutifully ignoring them. Wendy had her boots up on the counter, a magazine hiding her face. Dipper took a moment to compose himself before walking up to her.

"Hey Wendy, did Stan tell you about the new guy staying here for a while?"

The redhead shuffled her magazine closed and looked at him curiously.

"No, what new guy? Is he working here?"

"No, he's just staying in town for a while. I guess Mabel and I are supposed to make sure he doesn't get into trouble or anything."

Mabel nodded seriously. Wendy snorted.

"Get into trouble? What is he, six?"

"More like sixteen, actually."

"Oh. Teenagers, small children, either way trouble is a factor, I guess."

Mabel nodded again, sagely. Whilst still cradling her pig. She then went to fish around in some of the boxes on the other side of the store, looking for something or another.

"Heheh, yeah. Have you seen Soos around?"

"Nah, sorry man."

"It's fine, I'm gonna go look for him."

"Cool."

With Wendy's magazine back in place, Dipper headed outside, figuring he probably wouldn't find Soos inside if he hadn't already. The bell rang behind him and Mabel trotted up, carrying Waddles like a baby.

"Where're ya going, Dip?"

"Looking around for Soos. I want to warn him about our guest so he doesn't freak out or something else Soos-ish."

"O-K! I'm going to go see if Candy or Grenda are at the diner. Wanna look for Soos there?"

"That's a good place as any to start, I suppose."

Dipper shivered as he got into the golf cart, a feeling of foreboding making its way up his spine. Whoever this new guy was, he had a odd feeling about him. Who just showed up and volunteered to watch two kids and pay what was probably an extravagant amount of money just to stay in a tourist trap? It was confusing and suspicious. He couldn't risk letting him figure out about the books, after all, they didn't want another Gideon messing around with magical artifacts. He might even be like Robbie and run at the sight of anything supernatural, which would be just his luck, although better than the former option. Either way, he had to keep his book out of the new guy's hands. Or anyone else's for that matter. Of course, this guy wasn't used to Gravity Falls weirdness. He'd probably be scared off before the week ended, if they were lucky. Hopefully.

Somehow, it was never that easy.

Hope I didn't do too bad! If you liked it, you could tell me what you think!

Until next time!