Something inequine lurks beneath the frozen wasteland of Antlertica, Equestria's arctic territory. Twilight Sparkle and her friends are in the midst of setting up Equestria's most scientifically advanced research facility in one of the most remote locations on the planet...when some unexpected visitors arrive. What horror has been awakened? What long-buried secrets have been unearthed? And just how can you trust anypony when that pony just might be...a thing?