Toaru Kagaku no Railgun S

Mikoto Misaka is used to strange rumors in Academy City, but one of them refuses to disappear: researchers have supposedly created clones of the city's Level 5 Railgun. The truth is worse than the rumor. Thousands of “Sisters” modeled on Mikoto are being sacrificed in an experiment designed to make Accelerator the first Level 6 esper.

Believing her own DNA donation helped create the nightmare, Mikoto tries to destroy the project alone. Every laboratory she attacks is replaceable, every contractor expendable, and the Sisters themselves have been taught to accept death as data. Her desperate campaign isolates her from Kuroko, Saten, and Uiharu until another boy steps into the experiment, forcing Mikoto to confront the possibility that saving the Sisters may require trusting someone else.