A monster protecting a kid becomes the show's entire moral weight. Accelerator broke himself saving Last Order, and now he's stuck in the wreckage of that choice, watching her grow up while his hands won't stop shaking. The series doesn't pretend this redemption is clean or earned, it's a man spending twelve episodes learning that some damage never fully heals, and that might be enough.

Academy City ranks its espers from Level 0 to Level 5, and at the very top of its seven Level 5s stands Accelerator. Protecting the cheerful young girl Last Order cost him a bullet to the head and much of his power, and he has been recovering quietly in the hospital ever since. That calm ends when he saves the life of Estelle Rosenthal, a mysterious girl carrying a photo of Last Order. Soon he is pulled into a new conflict with Disciplinary Action, a sinister group rooted inside Anti-Skill, the city's peacekeeping force, which plans to use Last Order for a dangerous mission. With Estelle at his side, the self-proclaimed villain sets out to shield Last Order and defend Academy City. The spin-off is an action-heavy sci-fi story.