The main six ponies wonder why a new portal has opened at the giant tree where Opaline's castle used to be, and after some magical snowflakes turn them all into sparkly versions of themselves, they decide to go through and investigate. They find themselves in a winter wonderland, and despite the gradually shrinking portal, they decide to visit the nearby town. The place looks deserted at first, but they soon find all the residents celebrating inside the main hall. Once the main six make their presence known, the locals are startled and hide, but after some friendly assurance, two of them (a mare named Violet Frost and a stallion named Comet) open up to them and explain that they are "auroricorns" who live in the town of Starlight Ridge, and while they love their home very much, they have never been able to find out anything about other places. The auroricorns then cautiously agree to share some fun activities with them such as ice skating, sledding, and making ice sculptures. As they complete each fun activity, an aurora bursts in the sky, but the auroricorns become suspiciously apprehensive every time it happens. Even stranger is when a town bell rings and all the auroricorns suddenly insist on going to sleep and tell the main six to go home.
While the portal still remains barely open, the main six soon come to a consensus that they have been brought here for a good reason and decide to return to the town to find out what's going on. When they arrive, they discover all the auroricorns entranced with forced smiles and wandering around with some crystals plucked from the aurora bursts in the sky, with the monster causing it being some leopard creature named Allura (hope I spelled that right) with a bratty rabbit assistant name Twitch. The main ponies are able to break Violet Frost and Comet out of their trances by dragging them far enough away from town, so the two auroricorns explain how Allura had taken over control of Starlight Ridge by taking possession of some sacred relic (I can't remember what it was called) and has been enchanting them with some persuasion magic to force them to be happy enough to make aurora bursts and try finding the one star crystal that can open portals to other realms. With this information, the group of ponies decide the best way to stop Allura is to take back the stolen relic. They come very close to succeeding, but the plan falls apart at the last second, so Allura responds by enchanting the other ponies until only Sunny and Violet are left. However, when a mishap causes one of the enchanted ponies to break free just from slipping and falling into some snow, Sunny remembers an earlier remark that the snow of this realm has special healing properties, so they simply throw snowballs at their friends and they all do the same for all the auroricorns, overwhelming Allura so much that they're able to take the relic from her and she is forced to leave for now.
After letting Violet have the relic and thus become the new leader of Starlight Ridge, the main ponies are dismayed to discover the portal has vanished. However, another mishap breaks open the relic, revealing a star crystal that is able to open a portal, meaning Allura had what she wanted the whole time and never even realized it. As the main ponies prepare to return home, Comet declares that he wants to go with them and explore Equestria, so they agree to let him join them, with Izzy keeping that crystal so they can reopen the portal back to Starlight Ridge whenever they want to. Later, as the auroricorns celebrate, Twitch overhears them talking about how the outsider ponies were able to open a portal, so he shares the information with Allura, and with that portal still open, she and Twitch do not hesitate to go through.
Well, with the rumors that Make Your Mark was being discontinued at the end of this chapter, I was hoping for a final conclusion, like we pretty much got in the previous episode. Instead, it finishes off with a special that seems to set the stage for the next story arc, much like the special from Chapter 1 had done. However G5 is able to continue the story arc from here (especially with the introduction of Comet as apparently a seventh member of the main group of friends), one thing I anticipate from fan content would be shipping between Izzy and Comet, based on how those two frequently interacted with each other. I do at least appreciate how a one point during the battle that the main six ponies identify themselves by their supposed elements (Hope for Sunny, Kindness for Hitch, Courage for Zipp, Confidence for Pipp, Creativity for Izzy, and Empathy for Misty). I honestly don't have much more to say here (I guess my lack of sleep is really catching up to me now, and I'm pretty sure I might already be forgetting some details), so I'll just say that, overall, this special was rather average in comparison, with the current uncertainty of how the story will continue from here making it very difficult to really appreciate what it did manage to accomplish.