Winter Wishday is fast approaching, and the Mane 5 are all looking forward to the magical holiday celebration. Sunny can’t wait to exchange gifts with her friends under the wishing star that night in Maretime Bay, but finds that each of the Mane 5 have their own holiday traditions to celebrate as well. So, they hatch a plan to celebrate everypony’s traditions in one day with the help of Izzy’s newest upcycle project, a flying van they name the Mare Stream!
Together they takeoff through the snow to their first holiday stop, Hitch’s grandma Figgy’s house. There they build gingerbread houses and discover that, while Hitch assures them his grandma is very strict about her holiday traditions, it’s actually him who’s tied to his Wishday nostalgia. Afterward they depart to Bridlewood for Izzy’s unicorn tradition of placing her hoofmade ordainment on the Wishing Tree, a stop made even longer by Izzy stopping to tell every pony she sees “frosty shivers”, the traditional unicorn Wishday greeting.
Racing against the clock, they then head off to Zephyr Heights to attend the Wishday Carol Concert, which unfortunately runs way longer than expected. When it’s finally time to leave, the Mane 5 find that the snowfall has become so heavy that they can’t find the Mare Stream. With her detective skills and a little help from a book she borrowed from Grandma Figgy, Zipp puts together that the unicorns, not yet used to having their magic back, are accidently casting a spell when they say “frosty shivers” to each other. With this info, the Mane 5 journey back to Bridlewood to stop the holiday blizzard and barely make it back to Maretime Bay in time to exchange their gifts under the Wishing Star together. As the Wishing Star goes by, the Unity Crystals shine bright from the Crystal Brighthouse and send a rainbow up to it, creating a glorious light display in the sky over Equestria.