After inadvertently connecting to Kiyama’s mind, Mikoto learns what’s been motivating the doctor’s actions. Later, when the network goes out of control, Mikoto comes face to face with a monster!

The girls work to stop the monster before it reaches a nuclear power plant! Uiharu’s efforts slow the abomination down, but Mikoto might be the only person able to stop the creature’s rampage!

Saten and the other students who used the Level Upper learn some valuable lessons when they attend a special weekend workshop taught by Komoe and Yomikawa.

The midsummer festival arrives, and students are preparing to show off their school for friends and family. Misaka’s scheduled to perform a violin solo for the festivities - if her nerves don’t get the best of her!

The gang discovers that the recent wave of earthquakes is connected to a phenomenon called poltergeisting - and there’s a chance Uiharu’s new roomie might be somehow be involved.

Therestina reveals new information about her real identity and her master plan. Meanwhile, Kuroko and the gang vow to fight alongside Misaka in order to save the children jeopardized by Therestina’s activities.

Misaka and her friends reach the facility where the children are being held, but Therestina uses Capacity Down to take the Espers out of the fight. With everything on the line, it’s up to Saten to save the day.

Haru'ue joins Saten and Uiharu on a trip to the Garden of Learning to see Misaka and Shirai, as well as to do some shopping. They later go to visit Edasaki in the hospital, where she is undergoing physical therapy, when things take an unexpected twist.

Febri takes an instant liking to Saten, and is warm to everyone except for Misaka, much to her chagrin. At Judgment, Uiharu is unable to find any information on who Febri is, so arrangements are made to admit her into an orphanage as a "Child Error."

As Yomikawa takes over investigating the runaway security robots, Konori invites the whole gang out to take in a bath at a bathhouse. On their way home, a number of detours lead them to a confrontation with yet another, much more dangerous runaway robot.

With the revelation that Febri is synthetic, Misaka is determined to find whoever built her, and have them fix her. The investigation is stalled on all fronts, even with the help of her friends running down leads, until help comes from a surprise source.

Aritomi reveals his motivations for STUDY's project to Misaka. She also learns about Nunotaba's plight, and some of the details concerning what STUDY has planned at the Reach Assembly the next day. Will she be able to escape and put a stop them?

Shirai, Konori, Kongo and friends, and Uiharu and Saten confront the powered suits at the four Assembly sites, where they soon receive backup. Misaka and Febrie move to take on Aritomi directly, but he has one final surprise up his sleeve for them.