A direct sequel to Mass Core 2: Crimson Horizon.
Based on a Mass Effect crossover.
Two hundred seventy eight years have passed since Starlight Glimmer witnessed the destruction of Earth. In her long life, Starlight witnessed many things: the extinction of humanity, the Rise of the Alliance, the slow descent of the Council into rule by the shadowy Governors; most importantly, though, she presided over the transition of Equestria into a modern technological empire under the rule of the immortal goddess Twilight Sparkle.
This long peace, though, is interrupted when a dangerous criminal awakens from cryogenic stasis: the heretic Scootaloo, executed for crimes against the Empire. In response, Starlight is tasked with hunting down and eliminating a her former friend, only to find that there is far more to the mission than she initially expected.