A Certain Scientific Railgun Season 2 Episode 12

Tree Diagram

Mikoto resolves to destroy the Tree Diagram, the supercomputer responsible for the experiment's calculations, in the hope she may be able to stop them. Meanwhile, Touma encounters Misaka 10032, who coerces him into helping her look after an abandoned kitten she had found. As Touma goes into a book store to look for a book to help him with his own cat, Misaka 10032 goes off to observe Accelerator as he begins his scheduled battle with Misaka 10031. Arriving at Tree Diagram's control center, hoping to hack into Tree Diagram to order a halt to the experiment, Mikoto is confused to find it not only heavily low on security, but completely abandoned as well. Hacking into the system, she is horrified to learn the truth; Tree Diagram had been destroyed for months, with the experiments continueing regardless.