A Certain Scientific Railgun - Episode 022 - Level 6
Erii explains she and Banri were telepaths who grew up in a Child Error Orphanage before Banri moved. But recently, she began hearing Banri suffering and has been trying to find her. Mikoto explains about the experiment Harumi was involved to Therestina, who theorizes that Harumi's comatose students are the cause of the Poltergeist incidents. However this theory divides Kazari and Kuroko even more as the former thinks the latter is now blaming them instead. The next day, Mikoto learns that Harumi had been released from custody and later learns that if the Poltergeist situation isn't resolved, it could potentially destroy Academy City. Mikoto later goes to investigate one of Gensei's old facilities and encounters Harumi herself, who brings her to a hospital where all of her comatose students are under the care of Heaven Canceller. He explains that Gensei theorized that an esper can become a Level 6 by taking Ability Crystals made from the essence of comatose espers who lost control of their AIM fields. He gathered the Child Errors and bailed Harumi to try and find a cure, but without the 'First Sample', the first test subject of Gensei's Ability Crystal program, their attempts at waking the students caused Poltergeist incidents. Suddenly, Therestina and the MAR who followed Mikoto's movements to the location of Harumi and her students arrives, demanding that Harumi gives up the children to their custody. Forced to choose, Mikoto takes Therestina's side since she believes the children might have a chance with her, prompting the heartbroken Harumi to comply.