One mid-spring night, Twilight finds a strange spell in the library that doesn't appear to do anything at first. But deep within the Everfree forest, near the old castle ruins and deep in a hidden garden tomb, the spell takes effect. Three stallions awaken, with nothing but their names and the ability to telepathically communicate with each other. Their arrival will unearth some of Equestria's dark and hidden past, and possibly their own. For as they discover their own unique and strange abilities, another power ebbs from the darkness of the past.