"Accelerator" (一方通行 (アクセラレータ) Akuserarēta?, lit. "One-Way Road") is the thirteenth episode of the second season of the Toaru Kagaku no Railgun anime series and the 37th episode of the series overall. It was first broadcasted on July 5th, 2013. The screenplay was written by Tsuchiya Michihiro and is storyboarded and directed by Ishikawa Kensuke. The animation was co-directed Moroishi Kouta, Fujibe Ikuma, and Naoya Takashi.