Author's Note: Wiggidy wiggidy what's up dude-bros?

This is an AU of my own creation. It roughly blends together Gravity Falls and the CW Flash TV show. I'm still working out all the fine details, but everyone in this AU is three years older than they are in the canon (I.E. Dipper and Mabel are 15, Wendy is 18, ect.). Basically, when Dipper and Mabel were five, their parents were murdered by forces yet unidentified. They then went to live with Grunkle Stan, and have been raised by him ever since. As for the other details of this AU...well, you'll just have to keep reading!

If anyone's wondering about my other story, "Reverse Falls: Darkness on the Horizon," I've been meaning to update for a while, but college has been keeping me busy. I wanted to get something out today, so I decided to release the prologue of this story. Once this semester ends, though, you can bet that there'll be more Reverse Falls chapters on the way.

I do not own Gravity Falls. Enjoy!

Prologue

To believe what I'm about to tell you, you need to do one thing. You need to believe in the impossible. And I'm not talking your average, "Luke, I am your father," cubs winning the world series, oh-my-gosh-how-can-I-finish-this-paper-by-Friday impossible. I mean flat out weird, scratch-your-head-wondering-what-the-heck-happened impossible.

Can you do that?

Good.

It was a warm, sunny day in Gravity Falls. The wind blew gently on the rolling hills, creating small waves in a sea of green. The trees swayed slightly, making small whispering sounds as the wind passed through the branches. The smell of cooked meats filled the air, emanating from several grills in an area where families were playing and enjoying the world around them.

So, summer break. A time for leisure, kicking it back, and taking 'er easy.

Overlooking the valley rested a giant, colorful billboard at the top of a cliff. Illustrated on it were several pine trees, a winding river, and a sunrise. In big, bold letters it read "GRAVITY FALLS."

Unless you're me.

The serene setting was shattered as a lightly beat-up golf cart burst through the billboard, plummeting towards the hill below. The cart was occupied by two brunette teenagers, who were currently screaming at the top of their lungs. At the wheel was a boy in shorts, a dark, sleeveless jacket, and an orange t-shirt. The wind was blowing in his hair, revealing the Big-Dipper shaped birthmark on his forehead. To his right was a similar-looking girl wearing a colorful sweater and knee-length purple skirt. Unlike her companion, she had long hair, no birthmark, and the glint of braces emanated from her mouth.

The golf cart hit the ground, rattling the passengers. Wasting no time, the boy hit the gas, and the cart shot forward through the forest they now found themselves in. A large, shadowy creature landed on the ground behind the golf cart. It paused for a second, then chased after the teenagers.

"It's getting closer!" the girl screamed. The boy began to swerve the vehicle, steering the cart in evasive maneuvers with his right hand while his left hand clutched his left ear in pain. The girl held her stomach, as if trying to fight back a gag reflex. Bright sparks began to fly off of her, which were whipped behind them by the air to create a colorful trail of light for the golf cart.

See the boy in excruciating pain? That's me. The girl about to puke with sparks flying off of her is my sister Mabel. You may be wondering why we're currently fleeing from a gigantic mass of unspeakable horror. You might also be wondering why I'm in pain, and why there's freaking sparks flying off of my sister's skin like some sort of sparkler or welding tool.

The monster hurled a tree in the path of the speeding vehicle. It smashed a couple of feet in front of the cart, shooting splintered pieces in every direction. The boy swerved in an attempt to dodge the new obstacle, but it appeared that there would be little hope for that endeavor. The duo let out another panicked scream, bracing themselves for impact.

Rest assured, there's a perfectly logical explanation. Kind of.