Unbeknownst to all ponies, Octavia also works as an assassin, aside from her cello-playing. When she is assigned the job of assassinating the well-known DJ Vinyl Scratch, she is quick to hunt her down. However, she begins to befriend the unicorn.
King Sombra forms a new plan for taking over Equestria--he just needs to take over Tartarus first. But before that can happen, he needs a queen. And he decides Twilight Sparkle is perfect.