There are probably many homes in which a bright, octarine flash emanating from the next room would draw gasps, shock, even screaming. Most probably. This particular home was not one of them.
Stan Pines in particular, was not one to react terribly strongly to this sort of thing. To the untrained eye he would not seem to have even been aware the flash had occurred. Stan Pines had a very strict policy on moving, and it involved not doing it unless absolutely necessary.
The stately, rainbow-maned alicorn that strode into the room was not a practiced observer of Stan Pines, and so made some pains to make him aware of her entrance.
"Excuse me, human figure, I seem to have misteleported and I was wondering if you knew of a dimensional map I could use."
"Lady, the Shack's closed. Come back in the morning."
If the alicorn was taken aback, it did not show. She strode into the human's field of view, assuming that perhaps he hadn't noticed her form.
"Lady, you're blocking the TV, and like I said, I'm on down time."
The alicorn politely moved herself back out of Stan Pines' field of view, satisfied that he had seen her, but suddenly intrigued at how little she had perturbed him. She checked the television for curses, and in the process worked out its nature. A wire captured radiant energy, blended it with a local energy tap and then drew it on the screen. No curses. Just a classic nonmagical scrying device.
Her labyrinthine mind backtracked over what had been on the screen during the time she'd been in the room. Local drama. She seated herself and watched beside the strange man in his underthings.
After some minutes she decided to volunteer what she'd worked out. "Carol is definitely cheating on Mike."
"Ha ha! Yeah it's so obvious. Why doesn't she just paint a sign on her face."
Princess Celestia chuckled. Whoever this stranger was, she had already made up her mind that she could trust him. After a fashion. Assuming small amounts of money weren't involved, and she hadn't brought her wallet.
Dipper's unscheduled but predictable 10:45AM freakout broke Stan Pines' concentration on remaining studiously unconscious and he was forced to stop snoring effusively. This put him in a somewhat grouchy mood. He LIKED snoring effusively.
"Egh, Dipper, the thing is I don't CARE about the Gnomes-- What. You're doing that staring thing again."
Dipper's jaw hung open like a barn door. Stan knew damn well it was because of the alicorn. But acknowledging that wouldn't be funny. But you know what would?
"What, do I got something on my face?"
"AgaghaganfaALICORN. ALICORN. ON THE COUCH."
"Yeah of course she's on the couch, the floor's sticky."
Celestia yawned pleasantly. "Hello, Dipper, was it?"
"Oh my god you're an Alicorn and YOU TALK! THIS IS AMAZING."
Stan Pines had about 127 levels of uncomfortably awkward wince, although only four of them were visible to the naked eye. This one was only a 12. "Sorry about the kid, he's young, and full of desperation."
Celestia laughed gently. "Aren't the young always so?"
Stan guffawed. "HA! AIN'T IT THE TRUTH! Dipper, can you go into the gift shop and get my clothes? They should be on the counter."
Celestia directed a look at Stan.
"What? The collar was scratchy and it was a late night."
Celestia's smile had a certain deep subtlety that Stan decided meant this alicorn character was up to no good, which is to say that he liked her. Predictably, Dipper had slumped Journal number 3 onto the coffee table before exiting. He picked it up.
"Page 113 has a standard interdimensional rune table, but I don't know which system you're on so... see if this helps."
Celestia telekinetically flipped the pages and scanned the runes. She gave Stan a look.
"Yeah, I don't tell Dipper everything."
Celestia smiled. "So he may learn on his own."
That awkward wince went all the way up to 70 or so. "Yeah, but don't tell him or anything."
Celestia laughed. "Well, that would defeat the purpose."
"I know, right?"
Dipper arrived with Stan's clothes and gathered the journal, heedless of the fact that Celestia had set it down at an entire ten degrees off angle from where he had left it. She gave Stan another look.
She noticed Dipper had been talking to her, and ran back over what he'd been saying, slowing it down a little so she could catch all the words in that fast-forward talking thing Twilight often did.
"Oh my gosh this is amazing I've never seen anything as obviously magical as you wait. How did you get here was iiiiit..." he flipped through the pages of the journal, "the magic door of crispin?"
"Actually, I came here under my own power. And I do mean to get back quickly, as my kingdom needs me. But first, I need to obtain a Star Gem. I think there might be some locally, but they'd be in a cave where water falls in from above, and where the floor is slick with algae."
Dipper's eyes widened dramatically as he began thumbing through the book frantically. "Wait do you mean like-- THIS!?"
Celestia feigned surprise. "Yes, I think so!"
"OH MY GOSH THIS IS SO AMAZING MABEL GET YOUR GRAPPLING HOOK WE ARE GOING ON A MISSION"
The door slammed resoundingly shut just as Stan was adjusting his tie. "So, you able to figure out where you are?"
Celestia smiled. "Your brother's map was very good." Her eyes sparkled.
"Woh ho hoa," Stan said. "You ARE good. So tell me about yours."
"My what?"
"Your Dipper. You OBVIOUSLY have experience with his type."
Celestia laughed.
**
Dipper and Mabel set off on an adventure. Happens all the time. Hyperactive kids, let me tell ya.
**
"COME ONE, COME ALL, SEE THE PEGAUNICORN! the pictures are six bucks each kids"
The mysterious beast whispered in Stan's ear. The crowd ate that up with a freaking spoon. The whisper: "Pluck one of my mane's hairs." Stan feigned being taken aback.
"Won't that hurt?"
Celestia chuckled into his ear. "A little, but it will be extremely entertaining."
"The PEGAUNICORN has spoken to me, ladies and gentlemen. She has spoken, and offered up a blessing. A SINGLE HAIR from her incredible mane. With greatest humbleness do I take this SACRED gift."
Celestia's wince was on one of those levels not visible to the naked eye. The hair dazzled. It changed color. It really was the sort of thing you'd go on a quest to find. Stan whispered in Celestia's ear. "So, if I sell this will it, like, start a war or anything?"
There was a mischievous chuckle as she whispered back. "It'll evaporate in a day."
"LET'S START THE BIDDING AT TWO HUNDRED BUCKS!"
**
Dipper and Mable totally fought a giant bog monster and almost died or something. Probably. Dipper said they did so maybe a fifty fifty chance?
**
The Shack closed for the evening, Stan and Celestia stood by the counter swapping stories. Stan's laughter was much easier with the children "safely" adventuring. "Woa oh man, so at that point did you waste the dragon?"
"Pff, no, I told Twilight to do it."
"Heh. Twilight. She's like Dipper but, you know, purple."
Their laughter was cut short by a knock at the door. Celestia opened the door telekinetically. Dipper was at the door, Stan and Celestia could tell, despite being evenly coated with a mixture of mud and algae.
"I GOT THE STAR! Somehow! Also there are kind of some weird issues I have to work out."
"Ugh," said Celestia, forgetting herself. "What else is new."
The Star Gem clinked to the floor. "Oh great. You BONDED? GREAT, UNIVERSE. That's a good one, you know, because of COURSE the magical otherworldly being would decide to be best friends with Stan instead of me. EVERYTHING. IS EXACTLY. AS I WOULD EXPECT. I'm getting a shower."
The thing you have to understand is, it is entirely possible to feel genuinely and truly sorry for someone, and to wish that the pain and intensity of youth didn't have to be so painful and so intense, at the same time as you are laughing the muscles that attach your legs to you off.
As the sound of the shower kicked on and Stan and Celestia's laughter subsided. Celestia levitated the gem off the floor. "I'll talk to him before I go."
"Okay, yeah."
**
After he'd showered and pouted for a while Celestia talked Dipper down off the ledge, probably told him about Twilight because he'd be all over the idea of someone (and a GIRL too, HA HA!) like him getting magic training and ascending to princesshood (wow he really would, jeez) so that's for the best. Hopefully. I mean it'd probably end pretty bad if he tried to find Equestria somehow. Jeez.
**
Celestia returned to the living room where Stan was waiting, the chalk circles already scribed thoughtfully onto the floor. She smiled at the gesture. "Dipper seemed cheered somewhat when I left him."
"That's good. That's good. Listen, uh, this was fun. If you're ever in this end of the multiverse again..."
"I will most certainly stop by. Goodbye, Stan Pines. I am glad we met."
Celestia's normal glow swelled massively-- and she was gone. The room felt strangely empty. Stan smiled. "Nice knowing you too, sunbutt."