A Certain Scientific Railgun S

Mikoto Misaka and her friends are back, investigating rumors across Academy City. Soon, Mikoto discovers something terrifying: horrific experiments are taking place throughout the city, involving the murder of thousands of espers. Moreover, these espers are far from just ordinary people: they are clones of Mikoto herself. Feeling responsible for their treatment, she sets off to put an end to the experiments; however, the forces opposing her are much more dangerous than she anticipated, and Mikoto finds herself up against some of the most powerful espers imaginable. Toaru Kagaku no Railgun S continues the story of the Railgun as she desperately fights to put an end to the inhuman experiments...