Steins Gate › Season 1

Chapter 20 — Finalize Apoptosis

Despite Okabe knowing the location of the IBN 5100, Kurisu is against him trying to steal it, as it most likely will not change the world line. Instead, she suggests that Okabe stake out the location in order to find FB, with Moeka deciding to join him. As they observe the IBN being taken out, they follow it as it is passed along to several people, including Mr. Braun, before it ends up on a plane toward SERN's laboratory in France. Okabe, Moeka, and Kurisu confront Mr. Braun, who reveals himself to be FB and a Rounder who was forced to do their bidding to prevent harm from befalling Nae, after which he kills Moeka before taking his own life. Okabe uses Mr. Braun's cell phone to finally cancel out Moeka's D-Mail, returning to a world line where both Moeka and Mr. Braun are alive and he is able to once again obtain the IBN at the shrine. As Okabe gets Daru to hack into the SERN network to erase the data they have on them, he comes to the sudden realization that by doing so, he would have to return to a world line where Kurisu is dead. (Source: Wikipedia)