"Promise" (約束 Yakusoku?) is the fourteenth episode of the second season of the Toaru Kagaku no Railgun anime series and the 38th episode in the series overall. It was first broadcasted on July 12th, 2013. It's screenplay was written by Hanada Jukki, storyboarded by Sayama Kiyoko, and directed by Takashima Daisuke. The animation was co-directed by Sato Marina, Fuji Masahiro, and Taniguchi Motohiro. Meanwhile, Mikoto has been forced to bring out her final trump card, and now must make a difficult choice...