Miscalculation (誤算 Gosan?) is the 66th chapter of the Toaru Kagaku no Railgun manga was released on February 27, 2014. The chapter involves Shirai Kuroko's continued efforts against Kouzaku Mitori and her eventual victory, as well as Shokuhou Misaki's final ruse against Kihara Gensei.


Kuroko ambushes Mitori in the sewers. Mitori is shocked that her camera, out of the thousands around, had been hacked with dummy footage, to which Kuroko replies that she had the ultimate partner for that. Kuroko then declares that she has nowhere left to run. Cornered and with no time to call her Liquid Shadow puppet, Mitori reaches for her knives, thinking about how she used the sewers not only to hide but also in case she was tracked down, as the narrow passage limits teleportation. She then plans to shoot Kuroko with her ballistic knife when she teleports to avoid her first knife, taking advantage of her lag, taking both of them down if she attacks via teleportation instead. As Kuroko moves forward, Mitori throws the first knife, but to her surprise instead of teleporting Kuroko intercepts it with her hand. Not reacting fast enough, Mitori is then punched and then kicked down by Kuroko. Screaming, she lunges at Kuroko with the second knife but Kuroko teleports and kicks her in the back of the head. As she falls in battle, Mitori can only think of Dolly before losing consciousness.

Back with Gensei, Misaki's gamble pays off. Gensei collapses upon activating the release code, and Exterior begins to dissolve. Misaki regains consciousness and figures out what she must have done.

In a flashback, Misaki considered the low chance of her trapping Gensei with the facility's defenses, whether or not she still needs Exterior, the need to heal the Sisters of the virus and that it is likely her last chance to capture Gensei. As such, her gamble was using her power to switch her own concepts of the limiter release code with the self-destruct code, hoping that Gensei will mistakenly take the self-destruct code and destroy Exterior himself (Misaki couldn't do so herself because Gensei has the access rights to Exterior).

Thus Misaki wins against Gensei.

Major eventsEdit

  • Kuroko defeats Mitori.
  • Mitori is shown to have known Dolly.
  • Exterior is destroyed, leading to the defeat of Gensei.


By order of appearance:

New CharactersEdit

No new characters were introduced during this chapter.


New AbilitiesEdit

No new abilities were introduced in this chapter.



  • The chapter was serialized in Dengeki Daioh as Chapter 68 but was renumbered for the tankōbon version due to Chapter 65 merging three magazine chapters into one.[1]


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