Luna Walker has invoked Protocol E: Six of the most dangerous criminals in Equestria have been hired to apprehend the Trixie Lulamoon, aka The Puzzler, who is under lock and key in Aurora Asylum. Meanwhile, Twilight Sparkle, aka Mare Do Well, has her own mission: find Discord's dirty bomb before he gets the chance to detonate it. One problem: Discord is also in Aurora Asylum.
Story based on the DC animated movie, Batman: Assault on Arkham.