In a parallel dimension dedicated to the holiday of Nightmare Night and all things frightful, but kind, Twilight Soulshard, Lich Queen of Edeathstria has finally run out of fresh ideas to scare Ponyville, the town of Terrorsville's designated target for frights on Nightmare Night. Desperate for help, she seeks out an important figure in another realm dedicated to scares, one called 'Halloween' in the human world beyond a certain mirror, Jack Skellington. With Spike, she dares to go on a long-hoofed adventure to the Crystal Empire, the human world, and finally to Halloween Town and back.

Meanwhile, Rainbow Death prepares to try complete her 'reaping list' in plenty of time for her home holiday to spend more time with her friends. However, she may require a bit of help for this from her counterpart.

Also, Darksong Shadowbane, the Red and Black Alicorn and Most Feared Creature in All of Edeathstria gains the guidance of the rest of the Dead Six when it comes to trying to woo Nightmare Moon's loving heart horrible, festering heart.

Finally, Dr. Whoovenstein, shanghaied into fillysitting the Putrid Mark Crusaders, decides to take them and Derpy Stitched on a sight seeing tour… involving all of his favorite strange, wicked creatures of the Nightmare Realm. However, a group of Daleks and Weeping Angels may give him an unexpected surprise when they declare that they wish to take over the holiday, seeing themselves as superior in the art of fear.

Will the four groups be successful in their endeavors, or will Nightmare Night be a fright not be as horrible as they hoped?

~ A story set within the universe of the Nightmare Before Nightmare Night. You may or may not have to read it to get what's going on. Both are affectionate crossovers/parodies with/of The Nightmare Before Christmas and a slight bit of Whooniverse as well.