Dipper once again woke up to find a breakfast on his nightstand. He looked around his room to find Mabel standing by the doorway. She didn't look as tired as she was yesterday, though she was still nursing a swollen cheek, a black eye, a few wasp stings, a scarred leg, and various miscellaneous injuries. She still greeted him with a smile, showing her somewhat dented braces and chipped teeth.
"Good morning, bro bro!" said said, just as cheerful as ever.
"Morning, sis." said Dipper.
"So, ready to start Dipper Day 3? I sure am." said Mabel.
"Did you get some sleep last night?" asked Dipper, getting out of bed.
"Yeah, yeah. It's what you wanted, isn't it?" said Mabel. "Now, it's kinda raining outside, but that's not gonna stop us from going on a fun and life-changing adventure."
After breakfast and just before lunch, the twins went on a walk around the city in the rain. Mabel made sure that Dipper got an umbrella, a raincoat, a rain hat, and rainboots, while she insisted that she was fine in her usual wear. As they walked in the rain, she seemed to be intentionally to avoid standing under Dipper's umbrella, letting herself get soaked by the rain.
"Couldn't you just shapeshift yourself into... well, yourself, but wearing a raincoat?" asked Dipper as they walked through the rain.
"Eh, I don't think I need it." said Mabel, visibly chilly from being showered in rain. "I'm fine. A swarm of bugs like me probably can't even catch a cold!" she said, giving a bright smile.
Less than a second afterwards, a bolt of lightning shot from the cloudy sky, striking Mabel right in her braces. The flash was nearly blinding.
After the shock (the figurative shock, not the literal shock) wore off, Dipper frantically ran up to his sister, crying "Oh, gosh, oh no, oh gosh, oh no, oh no, Mabel! Are you okay?!"
Mabel sat up, her eyes rolling in a daze. She was rather charred and her long brown hair was frizzy, but she didn't appear to be seriously injured. The first sound out of her mouth was a long "Owwwwwwwww..."
Dipper immediately helped her up and pulled her into a hug. "Mabel, I'm so sorry! Do you need an ambulance, or-"
"I'm fine, and you've got nothing to be sorry for." said Mabel, giving a weak smile that showed her braces were crackling with electricity. "Now, how about we-"
Several small bolts of electricity surged from Mabel's braces and across her body. Mabel yelped as she involuntarily shapeshifted into a large pink and purple polka-dotted slug.
"Alright, this is kinda unexpected, but what do you wanna do next?" asked Mabel.
"We're going home." said Dipper.
Mabel gave as much of a shrug as she could being a slug and said "Okay, if that's what you want."
The two walked back home, Dipper making sure that Mabel was under his umbrella despite Mabel's insistence that she didn't need it. Periodically, more bolts of electricity surged across Mabel, causing her to involuntarily transform into things such as an orange and green stop sign, a giant spider, and what appeared to be a mass of utter nonsense.
When they got home, Dipper had told Mabel that she should just try to get some rest until the electric shocks wore off, but Mabel insisted that it was his day, and that he had worried about her enough already. Dipper then decided that for the rest of the day, they'd just spend time doing safe activities like board games and watching TV. Mabel was happy to oblige, but she still ended up injuring herself a few times with her currently uncontrollable shapeshifting.
Near the end of the day, Dipper remembered a question he had been meaning to ask Mabel for a couple days.
"So, is there a reason you got the idea to do this whole Dipper Day thing, specifically?" asked Dipper.
Mabel ran a hand through her still-frizzy hair and said "To be honest, I've felt pretty... pretty awful about a lot of stuff for a while now. But lately I-"
Mabel was interrupted by another bolt of electricity surging across her. With a yelp, she was turned into a squid. She continued anyway.
"Lately I've been having these dreams, and I don't wanna talk about what happened in them, but they sorta made me realize that I have a lot to make up for and-"
Mabel was again shocked by a bolt of electricity and transformed into what appeared to be an animate statue of herself. She continued.
"And since it's spring break I decided that now was the best time since we'd have a lotta time off to do what you want." said Mabel.
When she finished talking, she let out a sigh.
"I know that you've been feeling bad, Mabel, but you can't be so hard on yourself." said Dipper.
"I-it's fine, Dipper." said Mabel. "I should be this hard on myself. I won't learn anything otherwise."
With that, she walked out of the room. A few seconds later, another electric shock could be heard, accompanied by a yelp.
That night, Mabel again tucked Dipper into bed, giving him a small smile that showed her braces were still cackling with electricity.
"So, do you know when that'll wear off?" asked Dipper.
"I don't know, but I should be fine." said Mabel. "If you ask me, I think Dipper Day 4 will be the best one yet!"
"It's already been three days." said Dipper. "I think we're even now."
"No, I insist, you deserve an extra day." said Mabel.
Dipper said "Alright, if you're absolutely sure it's what you want-"
"It is."
"-then you can do a fourth day, but try not to get yourself hurt tomorrow." said Dipper.
"Sure thing, bro-bro. Goodnight!" said Mabel as she turned out the lights and walked out of the room. The darkened room was soon lit up by several electric flashes coming from the hallway. "I'm okay!"
"Goodnight, Mabel." said Dipper with a sigh.