A Certain Scientific Railgun Season 3 Episode 15 English Dubbed Episode Title:Promise.Episode Description:Mitori recalls her time in a facility where she ended up being befriended by Dolly, prior to her meeting with Misaki. After discovering that Dolly was a clone that was being fed experimental drugs, she was caught and confined for several months, leading to a building hatred towards the governing board. Back in the present, Misaki brings Mitori to meet Dolly's "little sister" that has inherited her memories, leading to a touching reunion between the three of them.