Here is a Phineas and Ferb and Gravity Falls crossover. Hope you like it!
A hooded figure skimmed quickly down the dark alley. The footsteps echoed around the alley, like rocks on a glass pane.
"Nice seeing you here." Said a creepy voice with a thick German accent. The figure stopped and turned around. A man in black coat faced the hooded figure. The hooded figure pulled its hood down. The orange haired teenager looked at the evil scientist.
"Doof!? Why are you here?" she asked, "I thought you were in jail."
The man in black sighed and took a step into the light. A scar covered his eye patch on his left eye and a smirk formed on his face.
"I was bored of jail, so I left so I could take over the tri-state area again." He said laughing. The girl turned and ran.
"Hey! Come back here you idiot!" he yelled, "Norm bots! After her!"
The girl ran as fast as her thin legs could carry her. She took raspy breaths as she ran faster. The Norm bots were about to catch her when a robot flew down and grabbed the girl. The girl looked up at her rescuer.
"Perry?"
The alarm beeped in the colorful room. The red-headed teenager, Phineas, sat up and pressed the off button on the alarm.
"Ferb, I know what were gonna do today!" He said looking at his step-brother Ferb, who had bright green hair. The red-head got up and raced down stairs.
"Well, looks like someone is happy!" their mother, Linda, said while flipping pancakes.
"You bet!" Phineas said sitting down at the table, "We're gonna plan the biggest new year's party ever!" He said smiling. He had planned this since last year's party. Phineas was always planning things. Like last weekend he had built an elevator to the moon! And for Isabella's thirteenth birthday he and Ferb had built a giant sandcastle with over a hundred rooms, yet oddly it had disappeared before his mom could see it. Candace was furious when it disappeared, but that always happened so Phineas and Ferb were used to it.
Phineas smiled. Tonight is gonna be great.
Dipper and Mabel Pines ran down the endless hallway. They rounded the corner and stopped for a breath.
"Why did you have to hit the demon with a rock!?" Dipper said harshly to his twin. Mabel shrugged.
"Why do you have to be so annoying?" Mabel asked looking at her brother and giving him a disapproving look. Dipper glared at her then looked around the corner. Dipper came face to face with a slimy green monster. Dipper screamed. Mabel looked around the corner. She froze. Dipper grabber her and ran. The slimy demon followed them down the hall. Dipper opened a door and pulled them inside then locked the door.
"Now what?" Mabel asked turning her flashlight on.
"We wait until it leaves, I guess" Dipper said open a journal with a three on top.
"Well maybe the journal has something to help us." Dipper said as he flipped through the journal. Suddenly the floor gave out and the both of them tumbling into darkness.
What do you think? Review guys! More chapter coming soon I promise!