Episode 13

The Dark Age (黒の時代,) is the 13th episode of Bungo Stray Dogs anime series. It first aired on October 06, 2016.

Summary
Learn about Dazai's past as an Executive Member of the Port Mafia.

Plot
Four years ago, a group of three friends used to drink together at a bar called Lupin's. These three men: Dazai, Sakanosuke Oda, and Sakaguchi Ango, were members of the Port Mafia, when Dazai was a feared executive, Oda a low-ranking member known for hardly ever killing others with his gun, and Ango an intelligence officer. However, these days are soon torn apart, with only a photograph to remember this soon after, as Ango disappears mysteriously and Oda is sent to find him. Oda locates Ango's residence at a hotel and finds a safe hidden in the ceiling tiles containing an old model of a gun -- a Graugeist. Meanwhile, Dazai uncovers an organisation known as "Mimic" with the Graugeist model as its members' emblem, threatening to destroy the Port Mafia. Meeting up later, Dazai recalls the night at the bar, when Ango explained that he just returned from clinching a deal, and deduces that his words were a lie.