A/N: Hey there, guys. Well, here it is-the debut of my Gravity Falls AU/rewrite of Undertale-Under Gravity! Originally I WAS going to wait until I finished 'Shadowfang14's Toy Story 2' to start on this, but I couldn't help it any more. This story was just begging to be written. And SFTS2 only has a few chapters left anyway, so I don't see the harm in leaving it for a little while while I start on this. I can't promise how frequently this story will be updated though-what with me still looking for jobs and everything. Plus, confession time-I've never actually played Undertale. I have to go back and watch Let's Plays of the game. Though I can promise you one thing-not everything will be like the game. Like with my FNAF fics 'Poor Little Souls' and 'A Place for Him', I'm taking certain liberties with the story-especially since this time around all the characters are actually from another series, so certain changes and stuff have to be made for their personalities and characters. Well, I hope you like it. Without further ado, here's Under Gravity!

Disclaimer: I own neither Gravity Falls nor Undertale. They're owned by Alex Hirsch and Toby Fox, respectfully.

Second place at the annual Gravity Falls Spelling Bee. That's how it all started. It didn't matter that Pacifica got only one word wrong, or that she'd done better than most of the other kids. There was no prize for second place-in spelling bees or in life. What's more, Pacifica was a Northwest. Northwests strove for nothing less than perfection. That was the lesson her parents had drilled into her head since before she could walk. And when Pacifica had tried to argue, her father had shut her up by ringing that stupid bell of his before sending her to her room. Once she was alone, Pacifica screamed into a pillow.

It wasn't fair! Pacifica was twelve years old; her parents shouldn't put so much pressure on her! She never even had any real friends because her parents didn't like her mingling with commoners. All her 'friends' were either hired or the children of her parents' friends and business partners. She knew they didn't care about her. None of them.

And then, lying there on her bed, Pacifica came up with a crazy idea. She couldn't be happy as long as she lived like this…so she'd run away from home. Filled with determination, the little blonde hopped off her bed and went to the closet. She couldn't very well leave home in her good clothes, after all. Someone might recognize her. Pacifica frowned as she moved aside skirts, tops, and dresses. Almost everything in her closet was flashy and expensive, likely to get her spotted a mile away.

Suddenly, her eyes fell on a particular item of clothing. A pink-and-blue striped sweater she'd gotten as a Christmas present from her grandma a year or two back.

"Huh. Forgot I had this." She shrugged. "Not something I'd usually wear, but it'll do for now."

Pacifica pulled on the sweater, along with a pair of shorts. Once she was dressed, she went over to her door, opening it just a crack No one was outside. Pacifica opened her door a little wider. Wider. Then slowly, carefully, she slipped out. Pacifica started down the hall, eyes and ears alert. She gasped as she heard someone coming, and hid around the corner. The person, likely one of her family's servants, continued on his or her way, and once Pacifica was sure it was safe, she chanced a peek.

Nobody was there. Taking a breath to steady herself, Pacifica came out from her hiding place and went to the staircase, taking a listen. She couldn't hear anyone downstairs. She didn't see anyone either, which meant it was probably all clear. Squeezing the banister, she shifted her weight to one foot, placing it gingerly on the first step. Then she took another step. And another. In about twenty or so steps, Pacifica had reached the last stair. She climbed down, letting out a sigh of relief.

"Miss Pacifica?"

Uh-oh…

Pacifica turned around to see the butler looking at her.

"Um…I can explain…"

"What's going on down there?" Pacifica let out a squeak as she heard her father's voice. Without thinking, she ran to the big double doors, unlocking them to run outside.

"Pacifica Northwest! Get back here this instant!"

Pacifica ran outside, never stopping. She didn't know where she was going, and she didn't care. Anywhere was better than here. She reached the gate and started to climb…and then she heard it.

Ding-a-ling! Ding-a-ling!

On instinct, Pacifica froze.

Her father was there, the cursed bell in his hand and an angry scowl on his face.

"Come down here, Pacifica." He was mad. He only ever got that quiet when he was really angry. His wife was standing next to him looking just as angry (or as much as her overly-Botoxed face would allow her to). Pacifica couldn't help but shudder as she looked down at her parents. What were they going to do to her? Between the spelling bee thing and her escape attempt, they had to be furious.

"Get down here this instant!" Mr. Northwest snapped, having lost all patience with his daughter. "I won't have you embarrassing this family!"

That little declaration gave Pacifica the boost she needed.

"If I'm such an embarrassment," she started coldly, "You should be thanking me for getting out of your hair."

Pacifica shimmied up the rest of the way, then jumped down and took off running again. But her parents weren't letting her off so easy. Pacifica heard the sound of the gates opening, which meant that in a second her parents would probably be rolling out in their fancy, expensive car. The young girl picked up speed. She couldn't let them get her! She wasn't going back to that prison she called home!

In her haste, Pacifica wasn't paying attention to where she was going. She ran through the trees…and right into a large, dark pit.

A scream ripped from Pacifica's throat as she fell down, down, down into the darkness, faintly hearing her parents' voices.

A/N: Yeah...this was short lame. Sorry. But then, it was only the prologue. I wrote this forever ago...I can promise, the other chapters will be longer, and hopefully much better. Until then, let me know what you thought?