What's up, guys? 087-B here with the Season 3 premiere of Gravity Falls: Sinnoh Adventure!

A quick note before this chapter begins: I originally planned to post this on August 1st, 2014, because that was the air date of the Season 2 premiere of Gravity Falls, but my internet decided not to work for…reasons. Anyways, I used the time I had to write this chapter, but I took a break yet again to work out the plot for the rest of the story, as well as the teams of each character. The teams went through a lot of changes from when this story began, and some of the Pokemon changed kind of threw off the plot a bit, but I worked around it.

Oh, and another thing, I updated the character bios for this story on my profile. The descriptions have been updated, I added each trainer's favorite type, and I put what Pokemon they have on hand, what they have in their PC, and how many badges they have. These will be updated over time as the story progresses. But enough of my rambling…

Now, on with the show!

Chapter 21: Underground Bound!

That very next day in Hearthome City, Mabel, Candy, and Grenda decided to meet in front of the contest hall to discuss that day's plans. Soos and Lazy Susan decided to let the girls have fun and stayed at the Pokemon Center. Meanwhile, as previously stated, the girls were ready to discuss what they wanted to do that day, whether it be partaking in a Super Contest, challenging the Gym, revisiting the Amity Square, or-

"Going underground!" Grenda suggested. Mabel gave her a quizzical look.

"Going underground? What?" Mabel asked, wondering what the heck Grenda was talking about. What was so fun about going underground? Then again, this WAS the Sinnoh Region…

"Believe it or not, Sinnoh is known for having a vast underground system that spreads all throughout the region." Candy said. "Trainers can go mining and create secret bases down there! Some people have even found ancient Pokemon fossils!"

"Whoa, that sounds so awesome!" Mabel exclaimed, a wide grin spreading across her face. "But, wait…how do we get underground? Last time I checked, you can't punch through concrete…and I learned that the hard way." The girl shuddered at the thought but shrugged it off.

"We can always use my Explorer Kit!" Grenda said, revealing a beige/brown briefcase from her backpack. She opened it and inside were many pieces of mining equipment such as pickaxes and electric drills, mining helmets, maps of Sinnoh's underground, and many other things. "I got it from some weird underground enthusiast guy in Eterna City."

"Aw sweet!" Mabel said. But then another thought crossed her mind. "Wait, won't we get arrested for, you know, tearing apart the roads and stuff?"

"Not at all! In fact, this is actually what we use to get underground!" Grenda reopened her Explorers Kit and took hold of the interior of the top part of the kit. She pulled it down and a keypad was revealed, as well as a screen. "Going underground is completely digital with this kit."

"…I don't get it." Mabel gave Candy and Grenda a blank stare. The two girls rolled their eyes.

"Just let us show you." Candy said. She pressed a red button on the center of the keypad. Suddenly, a large black circle began to form underneath the three girls. Mabel was in shock (and some awe), obviously shown by the expression on her face, while Candy and Grenda continued to smile and remain calm. Then the circle 'gave way' and became a hole, causing all three girls to fall in.

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After a few minutes, Mabel's screaming came to a halt as she landed flat on dirt ground. She got up, shaking her head to get out of her daze, and looked around. Obviously she was now underneath the Sinnoh Region. The underground caverns had walls made of dirt and some stone, and the ground and ceiling were pure dirt. Wooden scaffoldings helped support the ceiling, and attached to said scaffoldings were some oil lanterns and blue pipes with vents on them, most likely to ventilate oxygen. The place appeared to be a giant maze with many large paths and a few small indent-sized paths between walls as well. The hole they fell through was now gone, obviously proving the fact that technology sent them down here.

"Welcome to Sinnoh's Underground!" Grenda said as she and Candy got up. Mabel looked around again.

"…it looks boring." She said.

"Actually, it's far from boring!" A voice said. The three girls turned to see Roark, the Oreburgh City Gym Leader.

"Roark? What are you doing down here?" Candy asked in confusion.

"Why wouldn't I be down here? I'm quite the fan of fossils!" Roark said with a grin. "Mabel, Candy, and Grenda I presume?" The three girls nodded.

"Candy and I are introducing Mabel to the wonders of the underground." Grenda said. Roark adjusted his glasses.

"Well I hope she enjoys it down here." He said. "There's a lot of treasures down here you can find." Mabel's interest piqued.

"Treasures? What kind of treasures?" She asked. "I already know you can fossils down here."

"You can find more than fossils down here, Mabel." Roark said. "You can find fossils, yes, but you can also find colored shards, evolutionary stones, type plates, Heart Scales, Everstones, and a lot more things!"

"Whoa! Awesome!" Mabel said in awe. "I wanna find all those things you just said!" Roark chuckled lightly.

"Well go on ahead and do that, I'll leave you to it." He said before starting to walk away before stopping. "Oh, I almost forgot, you can dig into the walls and make secret bases." Then he walked away once more, leaving Mabel in complete awe.

"This is the bestest place ever…" She muttered. She then turned to face Candy and Grenda. "Girls, we've got a job to do!"

"What kinda job?" Grenda asked.

"We have to make the best secret bases ever." Mabel proudly said with determination. "And we're gonna find a whole bunch off treasure!"

"Yeah!" Candy and Grenda exclaimed in unison, pumping their right fists into the air. Mabel pulled a drill out from Grenda's Explorer Kit and pointed it towards a wall. Before the girls could stop her, she turned it on. The back of the drill backed up into her gut and sent her to the ground. The drill fell and shut off as well.

"…yeah, I don't know what I'm doing." Mabel muttered.

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An hour later, Candy and Grenda finished teaching Mabel the basics of exploring the underground. Now they were waiting for Mabel to exit her secret base, which she had just dug out and decorated with dolls that the two had given her.

"Um…Mabel? You alright in there?" Grenda called out. A moment passed and the boulder that blocked the entrance shifted to the left a bit and Mabel squeezed out from the small opening.

"Well, my base is complete!" She said proudly. The two others smiled.

"Awesome! Can we see it?" Candy asked.

"Sorry girls, but there's a secret password involved on getting in." Mabel explained. "But I'll tell you it so you can come in at any time." She whispered the code into the girls ears. "Anyways, what now?"

"I think we should go digging for treasures now." Grenda suggested. The others smiled again.

"Sweet! What can we find? Diamonds? Pearls? What about rubies! Sapphires! Emeralds!" Mabel continued to call out random gemstone names before Candy stopped her.

"Actually, there are different kinds of treasures found down here." She said.

"Instead of finding gems, you find these sphere things." Grenda explained, showing a bright red spherical gem-like object. "They're still pretty cool though."

"You can find blue, red, and green spheres, and you can find them in many different sizes." Candy explained. "You can also find rare prism spheres and pale spheres."

"Awesome! I wanna find a bunch!" Mabel exclaimed. She closed up her secret base, then took out her drill, sprinting off deep into the underground, the other two girls quickly following behind her. They followed her for sometime before she stopped. "…wait, how do we find them?"

"To find treasure, you gotta find a sweet spot in the walls." Grenda explained. "And to find a sweet spot, you gotta use a radar." She took out a yellow oval and pulled it apart in the style of a map, revealing a digital screen that showed a map of the underground. Some areas on the walls nearby began to shine on the screen. "These yellow stars are sweet spots that have stuff in them."

Mabel was already a step ahead and was drilling into the wall nearby on her right. She continued to drill for a few minutes before she shut said drill off and began to pull at the weak, crumbling rocks, revealing a large sized star shaped sphere colored blue and a large sized slightly bumpy circular sphere with a pale coloring. She pulled them out of the rocks and stared at them.

"Whoa, a prism sphere and a pale sphere!" Grenda exclaimed. "I've never seen ones as big as those!"

"Wow, those are super rare!" Candy exclaimed. "You should hold onto those!" Mabel looked at them for a while before placing them in her backpack.

"The prism sphere is going to Dipper, whenever he shows up." She said.

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A few hours had passed, and during that time, the girls had continued digging up treasures and designing their secret bases. Mabel managed to uncover two fossils, and she figured she would give one to Soos and keep one for herself, considering Dipper wasn't around at the moment. Mabel was still digging when the two other girls approached her.

"Hey Mabel, I think we can head back up now." Grenda said.

"Yes, I think we have found enough things for now." Candy said. "We can come down again and go digging for more treasure later."

"Alright, just let me finish up here." Mabel said with a small grin. Candy and Grenda nodded and proceeded to walk back towards their secret bases.

The girl continued drilling into the wall before noticing something dark blue glistening underneath some of the rocks. Curiosity got the better of her as she turned off her drill and began to pull at the rocks, trying to get a better glimpse of what was underneath. What she managed to find was some sort of dark blue marble like object, and inside of it, a black DNA strand of sorts. She stared at it for some time, wondering what it was.

Then she put it in her pocket and, taking her drill, walked off towards the girls.

-(End Of Chapter)-

…I totally felt like I made Mabel a bit OOC in this chapter.

Anyway, thus ends the chapter that starts Season 3! Sorry it was short, but man, it feels so good to be writing this story again! Thanks to all of my fans who have stayed with this story through the long hiatus (even though I prefer to call it a 'Season Break')!

Oh, and before I forget, here is this chapter's decodable cipher. See if you can crack it:

PDEHO'V VHFUHW SDVVZRUG LV VSDUNOHV

Anyways, with the cipher out of the way, I hope you have enjoyed this chapter, reviews are highly appreciated, and as always…

Stay Tuned!

~087-B