Silver Stream, a wintergreen colored pegasus from the western Equestrian town of Foalsom, befriended the Doctor on his exploration of Equestria. Months after they meet, Silver Stream was possessed by the nightmare entities and is transformed into the dark avatar of destruction, Nightmare Typhoon. Two pegasi named Frost Lace and Compass Rose witness this transformation and Frost Lace was captured and became Typhoon's Right hoof pony, Nightmare Blizzard. Compass Rose escaped and now accompanied by Princess Luna, The Doctor and the mane six, they must travel throughout Equestria to search for the secret to defeat this threat before it engulfs all of Equestria.