The second season of Toaru Kagaku no Railgun. 
 
Something sinister is going on in Academy City. The shadows are filled with whispers of an organization cloning super-powered students known as espers. High-ranking master of electricity, Mikoto Misaka, laughs off these stories until she comes face to face with a copy of herself. After learning that these clones - her sisters - are being systematically murdered in a series of experiments designed to turn a sadistic killer into the strongest esper in history, Misaka vows to save her copies and destroy the organization responsible for the project. 
 
As Misaka prepares to face off against the organization’s power-hungry esper, she discovers that she wasn’t the only victim of the scientific forces conspiring within the city - and that’s something Misaka and the girls of Judgement simply won’t stand for. 
 
(Source: Funimation)

Episode 1 - Electromaster

Episode 2 - When Working Under a Hot Sun, Rehydration is Essential

Episode 3 - Tokiwadai is Targeted

Episode 4 - Urban Legends

Episode 5 - A Certain Pair of New Trainees

Episode 6 - Everyone is Proactive When it Comes to This

Episode 7 - Abilities and Powers

Episode 8 - Level Upper

Episode 9 - Majority Report

Episode 10 - Silent Majority

Episode 11 - Dr. Kiyama

Episode 12 - AIM Burst

Episode 13 - A Bikini Divides the Eyeline Between Top and Bottom, But a One-piece Shows Off the Figure, so They Only Flatter the Slender

Episode 14 - Special Workshop

Episode 15 - Skill Out

Episode 16 - Academy City

Episode 17 - Tsuzuri's Summer Vacation

Episode 18 - Asunaro Park

Episode 19 - Midsummer Festival

Episode 20 - Poltergeist

Episode 21 - Voices

Episode 22 - Level 6

Episode 23 - What Is It You See In Your Eyes Right Now?

Episode 24 - Dear My Friends

J.C.STAFF

Funimation

Movic

ASCII Media Works

Geneon Entertainment

Warner Bros. Japan

AT-X

A Certain Scientific Railgun S