At Canterlot High in the human dimension, Sunset Shimmer joins her friends, Rainbow Dash, Applejack, Pinkie Pie, Rarity, and Fluttershy in the cafeteria.

Applejack: So how was the tour?

Sunset Shimmer: I don't know. I mean, these girls, they were... There was something off about them.

Pinkie Pie: Like, off like this? Or off like this?

Rainbow Dash: Maybe we should just let her tell us.

Sunset Shimmer: That's just it. I can't put my finger on it. They just acted sort of... strange around me. Maybe someone already talked to them. Told them about what I did. sighs So much for making a good first impression.

Fluttershy: Uh-huh. Oh, that's probably not it.

Outside the cafeteria, The Dazzlings, Adagio Dazzle, Aria Blaze, & Sonata Dusk have a brief argument before they enter. With their beguiling voices & arousing song, The Dazzlings convince the students of Canterlot High to turn the showcase into a Battle of the Bands. As they sing, tensions rise among the students, causing them to argue. Sunset & her friends are unaffected.

Pinkie Pie: Ohhhh! They’re that kind of weird…

Sunset Shimmer: I need to tell Twilight about this.

Meanwhile, in Equestria, Twilight Sparkle, Rainbow Dash, Applejack, Pinkie Pie, Rarity, and Fluttershy were at Twilight's castle. Twilight going to the main entrance to open the door.

Delivery Pony: Excuse me, Princess. Where do you want all these books from Princess Celestia?

Twilight Sparkle: The library. Third door on the left.

Delivery Pony: Even this one that's glowin' and vibratin'? He holds up a book that's glowing. Twilight brings it in and reads it as the others watching.

Twilight Sparkle: It looks like a message to Princess Celestia from my friends at Canterlot High.

Rarity: How is that even possible?

Twilight Sparkle: I have no idea, but it sounds like they need my help. The way Sunset Shimmer described them, I think these new girls sound an awful lot like... the sirens. They're three beautiful but dangerous creatures who had the power to charm ponies with their music. To maintain this power, they had to feed on the negativity of others. The more negative energy they consume, the stronger their voices become, and the farther they could spread their dark magic. But Star Swirl the Bearded wasn't having it. He found a way to banish them to another world. One where he believed their magic power would be lost. That world must've been the one where my Canterlot High friends live.

Applejack: But Star Swirl must have sent them there ages ago. How come they're just surfacin' now?

Twilight Sparkle: I don't know. But if my hunch is right and it is the sirens who came to Canterlot High, this spell they cast is just the beginning. My friends need me. I have to get back to them.

Rainbow Dash: I hate to burst your bubble, Twilight, but the connection between their world and Equestria will still be totally cut off for a super long time.

Pinkie Pie: Okay, first of all, if there was bubble-blowing going on, why wasn't I told about it?! And secondly, if the connection is totally cut off, how was Sunset Shimmer able to get a message to Twilight?

Twilight Sparkle: gasps Pinkie, you're a genius! And the interval between the two points is defined as the square root of the sum of the squares of the separation between the points along three spatial dimensions.

Spike: Say what?

Pinkie Pie: Duh! She's gonna take the magic in here and put it in there. That'll make the portal open up so that whenever she wants, she can go from here to there. Here to there. Here there! Here—

Applejack: We get the idea!

Twilight Sparkle: Now to see if it works.

The Crystal Mirror lights up brightly, indicating that it works.

Applejack: Don't suppose we could join you this time around?

Twilight Sparkle: Better not. It could make things confusing if Canterlot High suddenly had two of all of us. And we'll need {{user}}'s help again since they're from the other dimension.