HI ALL! i really wanted to write this fic, so here we go!
Dipper and Mabel ran into the house. "Hi, Grunkle Stan, what's for dinner?" Dipper called. No response.
"Grunkle Stan?" Mabel called.
The twins walked into the living room. Stan was sitting on the couch, talking to a young woman with long, indigo hair and dark blue eyes and appearing to be in her mid-twenties. The woman was obviously upset about something, and Stan seemed to be in the process of calming her down.
"Who's this?" Dipper asked.
The woman was the first to notice the twins. She smiled weakly at them. "You must be Dipper and Mabel," she said. "I'm Celeste."
Mabel walked over to the pair. "Are you ok?" she asked. "How do you know Grunkle Stan?"
Celeste laughed. "Oh, we've known each other for a long time. I've always given him help when he needs it."
"And that's why you should let me help you this time," Stan said. "How do you know you'll find what you're looking for over there? What if that person comes back to steal the rest of your power?"
"Wait, power?" Dipper asked. She looked human, but then again, this was Gravity Falls...
Celeste shrugged. "Well, I am a demon."
Dipper's eyes widened. He looked ticked that a demon was in their home. Stan held up a hand. "Hang on a sec, Dipper! She's not like the Dorito, so calm down!"
Celeste chuckled. "Dorito... Cipher's gonna hate that."
"You know him?" Dipper asked, still cautious.
She nodded. "Trapped him in the mindscape a couple decades ago. Still, he gets his power from me... so, yeah, I know him."
"So, you're his mother or something?" Mabel asked.
"Or something."
"Why are you human?" Dipper asked
"Not all demons look like one-eyed triangles, Dipper. Some of us, such as myself, are still somewhat human. Of course, it helps that someone stole most of my power recently."
"Who?"
Celeste shrugged. "No clue. Couldn't see them, just heard some weird chanting. Instincts took over, and I fought to keep as much of my power as I could." She sighed. "Now I need to find a way to get it back."
"Are you going to go look somewhere?" Mabel asked.
She nodded. "There's a library off the coast. It doesn't appear on maps or GPS, and it holds more information on the supernatural than anywhere else."
"If it's not on maps or GPS, then how do you know where it is?" Dipper asked.
"Because I helped create this place. Max... it was his idea. He kinda reminds me of you. Curious, intelligent, always looking for answers." She stood, legs shaking. "Anyways, I'll be leaving for the library in a couple of days, as soon as I make some arrangements." She looked at Stan. "Ummm, I forgot where you keep your phone."
"Do you really have to go?" Mabel asked, eyes pleading. Celeste had been staying with the Pines family for the past three days, and now she was about to start making her way to what Dipper had started to call "the Secret Library."
To be perfectly honest, Dipper didn't want Celeste to leave either. She knew a TON about the secrets of Gravity Falls, and some secrets about the journal as well. She was also really cool, and more than happy to teach Dipper some techniques he could use to protect himself.
But he didn't want to say goodbye. Which is why he was watching everything from inside the Mystery Shack.
Celeste nodded. "I need to do this, sweetheart. Whoever stole my powers, they can't be good. Unlike Bill, I don't normally make enemies, so they must have something serious planned."
Mabel nodded. A taxi pulled up in front of the porch. Celeste grabbed a backpack that was full of clothes and supplies and started to leave.
"Wait!" Dipper shouted, running out the front door. Celeste... he'd only known her for a couple days, but she'd been so nice to him and Mabel, almost like an older sister. Before he realized what he was doing, he was hugging the former demon.
She knelt down to face Dipper eye-to-eye, handing Dipper a slip of paper. "My cell phone number. I'll use it too keep in touch, ok? Call me whenever you want."
"Really?!"
She smiled. "Of course, kiddo. Be careful, both of you."
Then she left.