EP 01The Lone Swordsman and the Famous DetectiveSecurity police officer Fukuzawa Yukichi arrives at work to discover that his client had been assassinated. The assassin is already apprehended by the time he arrives, but something doesn’t quite seem right.
EP 02The Day Is a Dream, The Night Is RealFukuzawa gives Rampo a pair of glasses, claiming that wearing them would activate his ability to instantly determine the truth of any situation, and taking them off would give him the ability to tolerate the stupidity of the ordinary person.
EP 03The Secret Founding of the Detective AgencyRampo gets a ride to the police station, but the officer doesn’t seem to be who he says he is.
EP 04A Perfect Murder and Murderer (Part 1)Kunikida is being held for a murder that Rampo is certain he didn't commit. Meanwhile, Poe is determined to solve a murder mystery that has had the poilce stumped. Rampo has some thoughts on that situation, too.
EP 05A Perfect Murder and Murderer (Part 2)The last page of the manuscript received by Poe appears to have been a photocopy. Rampo seems to know why, but there are still more mysteries surrounding the death of the author.
EP 06Tragic SundayA group called the Decline of Angels spreads terror with several murders and the Armed Detective Agency is the one who must uncover its role to discover and stop the wave of terror.
EP 07Dogs Hunt DogsMembers of the Armed Detective Agency have been framed and now all become suspects in a terrible crime. It won't be easy to get away, especially when the Hounds squad is after them.
EP 08You, a Child of Sin; I, a Child of SinThe president of the Detective Agency is arrested, and Kunikida is missing after having blown himself up with a grenade. Meanwhile, Atsushi and Kyouka are on the run, looking for a way to defeat the true mastermind: Fyodor.
EP 09A Dream of ButterfliesPort Mafia boss Mori wants Yosano to join them in exchange for assisting the Detective Agency through their crisis. Yosano reveals why she would rather not.
EP 10In Lament of My Wingless BodyTanizaki, Miyazawa and Yosano head to the site where Yosano is scheduled to be handed off to the Port Mafia.
EP 11JailbreakAtsushi and Kyoka help Mushitaro escape. However, they get surrounded by the Bureau, led by Ango Sakaguchi.
EP 12Bungo Hound DogsSuspecting that Lucy is cooperating with the terrorist organization known as the Armed Detective Agency, Jouno and Tetchou pay a visit to the cafe at where she works, in hopes of tracking down Atsushi and Kyouka.
EP 13SkyfallTeruko goes head-to-head with Sigma. Tachihara rethinks the Agency’s innocence after re-infiltrating the Port Mafia.The fourth season of Bungou Stray Dogs. No longer concerned with military affairs, Yukichi Fukuzawa intends to act as a lone bodyguard-for-hire, making use of his deadly swordsmanship. However, things are not going as planned for his freelance business, and that is when he crosses paths with a mouthy boy named Ranpo Edogawa. While their initial interactions are intertwined with a bizarre murder mystery, the aftermath prompts the formation of the Armed Detective Agency. Presently, Ranpo finds himself chasing down a gifted individual with the dangerous ability to execute the perfect crime. But as the great detective unravels the case, he soon discovers an elaborate plot to obliterate the Agency in its entirety. Although forewarned of the trap, the Agency continue their pursuit of the criminals, only to end up framed for the crime themselves. Now branded as wanted terrorists, the remaining members must find a way to prove their innocence—even if they must turn to sworn enemies for assistance. (Source: MAL Rewrite)
