"August 19, Part 1" (八月十九日① Hachi-gatsu Jū-ku-nichi ①?) is the 26th chapter of the Toaru Kagaku no Railgun manga series.
The chapter opens with a debrief of the mission: there is high probability that an Electromaster that is going to attack the facility and they have to stop the attack and not inquire about the perpetrator's identity. Frenda then prepares her toys in the vents and upon hearing the intruder, prepares to attack.
Mikoto rushes into a large room and above her, Frenda's toys explode, making the ceiling on top of her. Mikoto redirects the debris with magnetism, but Frenda quickly follows up by igniting her fuselines. This corners Mikoto, but she is able to avoid being hit seriously and upon following Frenda's fuse-lines, deduces where she is. Rounding a corner, a ceramic doll explodes, but Mikoto is able to disintegrate the ceramic.Mikoto chases Frenda up a staircase and upon it exploding, is able to use her magnetism to continue walking.
The chapter ends with Mikoto chasing Frenda into a large room, 'cornering' her.
Adapted from? which chapter of novel
refs to previous chapters