A Certain Scientific Railgun Episode 21 English Dubbed Episode Title:Voices.Episode Description:Following the Poltergeist incident, Mikoto wonders if Kiyama is once again involved, though Kuroko reminds her that Kiyama is supposedly still in custody. Kuroko instead suspects Erii as the cause, since most of the Poltergeist attacks have been occurring at places she has been. Both of them do a clandestine background check on Erii and learn that, despite being a Level-2 telepathic esper, she can exhibit Level-4 powers under certain catalysts. Kazari takes Erii to the park, where Erii explains that she had been looking for a childhood friend. Erii goes into another trance, and a violent Poltergeist attack occurs at the park. Kazari becomes angry at Kuroko for suspecting Erii, so Therestina performs some tests on Erii at the MAR Base Research Laboratory to prove her innocence. Upon waking up, Erii explains to everyone that she falls into a trance upon hearing the voice of her friend, Banri Edasaki, who apparently is another telepath. When Erii shows everyone a photo of Banri inside her pendant, Mikoto recognizes Banri as one of Kiyama's Child Error students who went into a coma.