Later that day, Starlight is off in the garden sitting among the statues. Inside the castle, Twilight deals with a possible brink to Equestria's defenses. How she wishes the royal sisters were around to help! Twilight, following her instincts, goes and grabs Starlight and the two go off to see what the threat on Equestria's edge may be.
A few hours later, the two arrive at Equestria's edge. Once there, they're surprised to see that the threat to the border is a herd of a creature similar in biology and anatomy to a changeling except it's not a changeling. Twilight boldly asks what the creatures are and what they're doing outside Equestria.
"What are you? What are you doing here?" asks Twilight.
"We're shifters, we can change our appearance and physiology on a dime," speaks up their leader, who is a male about a foot taller than the rest of them. "We're here to take over Equestria."
"Not on my watch!" replies Twilight. She shoots her magic at them.
"But princess," replies the one, "we soak up all magic. Nothing can defeat us."
Twilight stares at them. She's frightened now as is Starlight. The two retreat back to the castle. They don't know what to do. If they can't defeat the creatures with magic, how exactly are they going to defeat the creatures? Twilight goes to the library to see if the books there have any information about shifters to possibly use against the creatures.
In the library, Twilight soon finds a book on the shifters titled Shiftlings: Everything About Their Biology, Physiology, and Appearance. She skims it over and soon finds exactly what she needs to stop the creatures. "To stop the shifters, use black crystals to capture them inside." Twilight then hops on the train to the Crystal Empire and soon recovers some of the black crystals from her sister in law Cadence's archives. Cadence then wishes Twilight well, gives her a hug, and sends her on her way. A few hours later, Twilight returns to Canterlot. There, she meets up with Starlight and they go to confront the creatures once again, this time prepared.
A few hours later, they arrive back on the Equestria border with the box in hoof. They pull out the black crystals as the shifters shift into their attack forms. Upon transforming, the shifters are sucked into the black crystals and trapped. Twilight then puts the creature filled crystals into the box and puts an unbreakable seal spell on them. Twilight then returns the creature filled box to Cadence in the Crystal Empire. The two then hide the box in Sombra's inescapable trap hidden below the castle. Once that's out of the way, the two spend the day together before parting ways a half hour later. Twilight is just glad they got the threat out of the way long before the royal sisters return.