During a long-put-off visit to see her brother and sister-in-law during Hearth's Warming, Twilight simply cannot catch a break! It's bad enough that the Crystal Heart begins to malfunction, casting Gloom and Doom (While Things Go Boom!) all over the land instead of its usual Love and Harmony, during the Holiday no less, but NOW, when it is STOLEN, an old Enemy has also resurfaced, thus adding to the "fun!"

Can Twilight solve this Mystery?! Can she and Sombra work together to save Hearth's Warming?! Did Sombra's heart grow THREE* sizes that Day, thus filling him with Love and Kindness?! Will Tiny Tim ever walk again?!

...yeah...I'm gonna do you a solid and go with...no...no to all of these...

Sombra and Twilight, and they have to go on a Christmas adventure with a common goal.