When Luster Dawn moved to Ponyville, she didn't expect to connect with an unlikely group of friends: excitable Kirin Half Moon, cool-calm-collected dragon Alex, shy griffon Gemma, rough-and-tumble changeling Stinger, bombastic yak Magnus, and reluctant pegasus Aurora. However, she doesn't have long to get used to her new situation before she and her friends are called far beyond the borders of Equestria to deal with a long-thought vanquished foe and discover a long-forgotten and dark chapter in Equestrian history...