This is a cross-over between "Gravity Falls" and "Scooby-Doo Mystery Incorporated." All characters belong to Warner Brothers and Disney, not me. The road trip of Mystery Inc, formerly of Crystal Cove, takes them to Gravity Falls, Oregon.

Mystery Shack

"Look gang," said Fred, pointing to a sign on the road. "Visit the world-famous Mystery Shack in Gravity Falls, Oregon. You will be amazed."

"That sounds terribly fake," said Velma.

"Like, we'd better check it out anyway. We're desperate for mysteries since Crystal Cove has been rewritten without them," said Shaggy.

"We used to bump into mysteries everywhere," said Daphne "Now they're so rare..."

"Rare," said Scooby-Doo. "I'd like rare roast reef, rokay?"

"We promised ourselves we'd hit every mystery on the way to Miskatonic University," said Fred.

"And every fast-food joint, don't forget," said Shaggy. "Look at that sign: 'Visit Greasy's Diner in Gravity Falls, Oregon. We have food.'"

"Re have food!" said Scooby. "Yummy!"

"Oh, dear," said Daphne. "More indigestion."

"Like, Scoob and I never get indigestion," said Shaggy.

"But we do," said Velma.

"Then you check out the Mystery Shack while we eat," said Shaggy.

They dropped off Shaggy and Scooby at the diner, and drove a short distance down the road to the Mystery Shack.

"Mystery Hack," said Velma. "They've lost a letter on the ground. This looks like the worst sort of tourist trap."

"Maybe we should expose it as a fraud?" Fred suggested.

"No. My parents used to run this sort of place," said Velma. "Now they run a regular convenience store with a sideline in souvenirs. Maybe this will bring back old memories."

They got out of the car and approached the front door. An old man came out to greet them in a dark suit, wearing a fez and sporting a cane with an eight-ball on top.

"Welcome, sightsuckers! I mean, sightseers. You've come to the right place. I am Mr. Mystery, owner of the Mystery Shack and your guide to its wonders."

"Not Mr. E?" asked Fred.

"Mr. Mystery, though that other name has a nice ring to it. Maybe I should take it," said Mr. Mystery.

"It's taken," said Velma. "What is your real name, if I may ask?"

"Stan Pines. Anyway, come and see what we have inside. You'll be amazed!"

The place was cluttered with an assortment of junk, like a fake jackelope, a "sascrotch", a picture of a horse riding another horse, and so on.

Stan showed them around, while a bored red-haired teenager read a magazine behind the counter, a young man wearing a brown baseball cap swept the floor and a young girl with braces and a big smile dusted the nick-knacks on the shelves, giggling to herself as she made the Stan Pine bobble-heads nod.

"We're Mystery Incorporated. We investigate paranormal incidents and monster cases of all kinds," said Fred.

"Yeah? I've never heard of you," said Stan.

"Nobody has, any more. We used to be big in Crystal Cove, California," said Daphne.

"Now we need a new case to reestablish our reputation," said Velma. "Any monster sightings we could look into? Reports of strange happenings in town?"

"I know of nothing like that," said Stan. "The best monster souvenirs are right here, but if you're not buying..."

He looked like he was preparing to shoo them out.

"Wait, Gruncle Stan," said the young man, coming over. "May I talk to them for a minute?"

"Time's money, kid. Better not spend it on non-paying customers," said Stan.

Shaggy and Scooby came into the store.

"Hi gang, we had a good light snack of two dozen burgers, three pizzas, and all the pies at Greasy's. Like, look at all this cool stuff!"

Stan looked at the new potential customer. "He's with you?"

"Yes," said Fred.

"Then you can talk to my grand-nephew here, Dipper Pines, while I give him the tour."

"I'll have a case of Pitt's soda, and all of those ice cream bars, and..." Shaggy said.

"Hi Dipper," said Daphne, bending down to greet him. "What's up?"

"H-hi," said Dipper, looking a bit red in the face. He looked back and forth between the girl behind the counter and Daphne.

"Tempted to get a new girlfriend besides Wendy, Dipper?" came a voice behind them. The smiling girl looked out from behind one of the shelves.

"Not now, Mabel," said Dipper. "These are experts on the paranormal. I need to consult with them about a monster."

"In most of our cases the monsters have turned out to be fake," said Velma. "But we've seen the real thing, too."

"You'll keep an open mind, then?" asked Dipper.

"Yes, but not so open that our brains fall out," said Velma.

"Brains," giggled Mabel. "My brother thinks my new boyfriend is a zombie who's going to eat my brains. But I'm really hoping he's a vampire."

"You've read the Dusk books?" Daphne asked.

"Oh yes," said Mabel. "I love them."

"What is your boyfriend like?" asked Daphne.

"Mysterious, dark clothes, with a hood over most of his face," said Mabel.

"Clumsy, shambling, and creepy," said Dipper.

"Oh, there he is now," said Mabel. "Hi, Norman! I'll be right there. Norman's taking me on a date out in the woods today."

"Be careful," said Dipper.

"Your brother's right, Mabel," said Daphne. "He doesn't have to be any kind of monster to be dangerous."

"He's perfectly nice. I'm not letting anyone spoil my summer romance with conspiracy theories," said Mabel, looking stubborn. She headed to the door.

"See you, Mabel," said the teenager behind the counter, smiling and giving her a lazy wave.

"See you, Wendy," said Mabel.

"Have a nice day," said Stan.

"Thanks, Gruncle Stan," said Mabel.

They saw her head towards the woods, with Norman staggering and stumbling behind.

"Your great-uncle doesn't have a problem with her going out alone with him?" Fred asked Dipper.

"No, but he's not very protective," said Dipper. "I've been taking some videos of Norman, trying to get evidence that he's a zombie. Watch them with me and I'll show you what I mean."

Dipper got his video camera and played back the short scenes he had recorded. Shaggy and Scooby gathered up their snacks and came over to join them.

"He seems to be very clumsy, all right," said Daphne. "But girls can find that endearing."

"The way he walks is odd," said Velma. "I'd say he was double-jointed, or..."

They came to a scene where Norman dropped one hand to the ground, picked it back up, and stuck it back into his sleeve.

"Aah! Zombie!" said Dipper.

"Zoinks!" said Shaggy.

"I'm starting to think it's a stack of midgets in disguise," said Velma. "But he's not what he seems, and that means she's in danger."

"Let's go after them," said Fred. "To the Mystery Machine."

As they crossed the yard, a large bald man handed Dipper a shovel, "For the zombies."

"Thanks, Soos," said Dipper.

"And here's a baseball bat, in case you run into a piñata," said Soos.

Dipper took the bat also, and they headed to the car.

"Would the golf cart be better at getting though the trees?" Dipper asked.

"I'm very good at driving this off-road," said Fred.

The gnomes Jeff, Steve, Carson, Jason, and Shmebulock had revealed themselves to Mabel and asked her to be the gnome queen. When she refused, Jeff said they were going to kidnap her. They fought her to the ground and began to fasten ropes over her, like the Lilliputians did to Gulliver.

"Don't tie her to the ground. Get ropes around her arms and legs. We need to get her to the crystals in the woods that give off the shrinking light," said Jeff.

"You jerks! I can't marry one thousand of you! What are you thinking?" Mabel said.

"Don't worry, honey," said Jeff. "We've got it all scheduled out. You only need to handle one hundred a day. Each will get intimate time with you every ten days, which seems perfectly fair and reasonable."

"One hundred a day? That would kill me," said Mabel.

"No it won't, darling," said Jeff. "We'll make you immortal, like us. You'll stay our young and beautiful queen forever."

"Help!" Mabel screamed. She fought the ropes, but they were too tight.

The Mystery Incorporated gang and Dipper found the place where the gnomes were holding Mabel captive.

"What are you doing to my sister?" Dipper asked.

"This is all a misunderstanding," Jeff told them. "Dipper, your sister is in no danger, she's just going to marry all thousand of us gnomes and be our queen for all eternity. Right, honey?"

"You guys are butt-faces!" Mabel yelled.

"Give her back!" Dipper demanded, threatening them with the shovel.

"We agree. Free your prisoner!" said Fred, who had the baseball bat.

"You can't stop us," said Jeff. "You have no idea what we're capable of. We gnomes are a powerful race!"

Dipper threw Jeff out of the way with a shovel. The members of Mystery Incorporated guarded his back as other snarling gnomes tried to close in, kicking and throwing the gnomes into the woods.

Dipper used the shovel blade to break the ropes holding Mabel down. She jumped up, and when Steve closed in she gave him a kick that made him throw up a rainbow.

"Come on, lets get out of here," called Fred, and they all dove into the Mystery Machine.

"Gnomes of the forest, assemble! Get our queen back!" called Jeff.

Gnomes spilled from the trees from every direction, and began to link up into a huge combined figure.

"Riant rome!" said Scooby-Doo.

"Like, don't wait until they're complete, Fred. Step on the gas!" Shaggy said.

The Mystery Machine charged down the road with the giant combined monster in hot pursuit.

They smashed through a "Visit Gravity Falls" sign and headed toward a small cliff.

"Watch out!" Dipper yelled.

"Don't worry, I've tricked this baby out," said Fred. He pressed a button that activated springs, and the van landed safely, if a bit roughly.

The race continued until the gnomes pulled up a huge tree and threw it ahead of the car, blocking the road. If they had been in a smaller car like the golf cart, they might have gotten around or under it, but as it was they had to stop.

The giant combined gnome raised its arms above the car. "Surrender our queen before we do something terrible," Jeff said. "Or, if you'd rather, we'll take the pretty redhead."

"You don't have to do that for me," said Mabel to Daphne. "This is my monster problem."

"Hey, I'm pretty too," said Velma. "Why doesn't anybody ever think of kidnapping me?"

"Hmmm," said Jeff. He held a mumbled conversation with the other gnomes.

"All right, if you're willing you've got a deal, honey," said Jeff. "What's your name?"

Velma popped open the skylight at the top of the van. "I'm Velma. Want to kiss the bride?"

"Sure I will," said Jeff. "Lean down, guys, so I can get on top of the van."

He came close, puckering his lips for a kiss, and then high-powered air blowers and fans popped out of the roof of the car.

"It's a trap, suckers," said Fred. "We've dealt with creatures made of swarms before. Compared to the Cicada Monster you're not that scary."

Jeff was blown back and he bowled into the others, loosening their grips. In a moment the gnomes were being scattered by the fans in every direction.

"You haven't heard the last of us," Jeff called as he vanished into the distance.

The other gnomes seemed disorganized without their leader. Fred revved up the Mystery Machine and jumped the log using the springs.

"Thanks, Mystery Machine gang," said Mabel.

"Mystery Incorporated," Velma said.

"And thanks, Dipper, for getting their help. I should have listened to you. It sucks that my first boyfriend turned out to be a pack of gnomes."

"Oh well, maybe your next one will be a vampire," Dipper joked.

Mabel gave him a playful punch in the shoulder, a pretty hard one.

"Like, I guess our work here is done," said Shaggy. "We'll drop you off at the Mystery Shack and get back on the road."

"You could stay longer," said Dipper. "I'm sure there will be more monsters and mysteries around Gravity Falls."

"There might be, but we try to keep on the move," said Fred.

"There used to be, like, a curse on us that attracted criminals to dress up as monsters all the time, to make cases for us to solve," said Shaggy.

"Really? How cool is that?" said Mabel.

"We're not sure the curse is still there, but it might be," said Daphne. "You'll have enough of your own mysteries without us creating more."

"You've got your own mystery gang, too," said Velma. "Dipper, you've got the book knowledge to be the researcher, like me. That was an excellent investigation you did on Norman."

"Thanks," said Dipper. "Can you give me any more pointers as paranormal experts?"

"In our experience a four-person team works best," said Fred. "I suggest you ask Wendy and Soos to come in on cases. They could be your equivalents to Daphne and me."

"What about me?" asked Mabel.

"Can you be, like, silly and babble a lot?" asked Shaggy.

"It's what I do," said Mabel.

"Then you can be the Shaggy of the team," said Shaggy.

"Do rou have a talking ranimal?" asked Scooby.

"No, but I'll look for one," said Mabel. "I'd really like to find a talking pig."

"Then you can be Mystery Incorporated, Gravity Falls branch," said Velma. "I'll give you my cell number in case you need a consultation by phone. If you really need us, we'll come back."

"Yay! We're Gravity Incorporated," said Mabel, with a big grin.

"Gravity Incorporated," said Dipper.

"Scooby-Dooby-Dooo!"