Decay of the Angel Saga

The Decay of the Angel Saga is the second saga in the Bungo Stray Dogs manga and anime series.

Synopsis
The Armed Detective Agency are victorious against The Guild. However, a seed of terrorism is planted in the city of Yokohama. Fyodor Dostoevsky and his allies enact their plans that'll throw not just Yokohama, but the world into chaos. As part of their plan, they set up the agency as worldwide criminals causing them to go on the run. With Yokohama and the entire world at stake, the Armed Detective Agency put their lives on the line to stop the terrorism orchestrated by so far, their greatest foes yet.

Summary
Fyodor and his Rats enact their plan to destroy the Armed Detective Agency and the Port Mafia. A cannibalizing ability belonging to one of Fyodor's subordinates infects the agency's leader, Yukichi Fukuzawa, and the Port Mafia's boss, Ōgai Mori. After forty-eight hours, the virus will destroy the hosts' internal organs, unless one of them dies before the virus outbreak, thus nullifying the other's illness. This starts an all-out battle between the agency and the mafia to save their respective leaders before it is too late. Fortunately for the two organization, Mori and Fukuzawa's former mentor, Sōseki Natsume, states that former agency member, Katai Tayama, has discovered the Rats in the House of the Dead's hide out. The detective agency and the Port Mafia found the enemy's base and the virus wilding ability user, Alexander Pushkin, is captured and his ability is deactivated, thus saving the two leaders. However, Fyodor is nowhere inside the base. As Fyodor makes his leave out of the cafe he's at, Osamu Dazai checkmates him and reveals that he had help from Francis Scott Key Fitzgerald's Eyes of God system. Fyodor is then arrested by the Special Division for Unusual Powers.

One month after the cannibalism incident, Doppo Kunikida has been charged for child murder during the incident. Ranpo states that Kunikida was framed by Fyodor and someone on his side erased the evidence that proves his innocence. Ranpo then vows to get him out of jail and clear his name. Ranpo, with the help of Edgar Allan Poe, successfully captures the evidence destroyer, Mushitarō Oguri, who turned himself in after Ranpo threatens he would reveal that the murder of his late friend was planned so his story book can be based off of it. The charges against Kunikida were cleared due to Mushitarō deactivating his ability.

As Mushitarō was on his way to prison, the police officer who was driving him there was shot by another officer. The "officer" is revealed to be Nikolai Gogol, an acquaintance of Fyodor and one of the 5 members of the terrorist organization, the Decay of the Angel. Gogol kidnaps Mushitarō and deactivates his evidence destroying ability, causing most of the evidence he erased to resurface. During the evening, Gogol and a group of hooded individuals hold various government officials hostage, leading the Armed Detective Agency into a trap. Ranpo learns from the Special Division's director, Santōka Taneda, that the Decay of the Angel stole a page from the Book and are planning to use it to frame the agency. The agency is at the door with the hostages on the other side and hear them screaming as they get cut to death by the chain saws. The people take off the hoods and reveal to be the detective agency. The detectives go on the run and the military's most powerful squad, the Hunting Dogs, hunt them down. Later on, in their pursuit of the agency members, the fifth and the last member of the Hunting Dogs was revealed to be one of the Port Mafia's Black Lizard commanders, Michizō Tachihara.

Atsushi and Kyōka obtain info about the Decay of the Angel's plans from Mushitarō. They have till the next full moon before they use the back of the page. Atsushi and Kyōka, with the help from Lucy, sneak into the Sky Casino to capture the casino's manager, Sigma, and make him reveal the location of the page. The Hunting Dogs continue their pursuit of the detective agency and have gathered intel that the latter is at the Sky Casino. Hunting Dogs' vice-captain, Teruko Okura, faces off against Sigma and easily overs him. Sigma released he can't save himself and the casino, so he plunges himself to fall down together with Teruko in an attempt to save the casino at least. Failing to try to take him in alive, Teruko lets him go and saves herself only to see Atsushi save Sigma. Atsushi tries to get Sigma to tell him where the page is at but is interrupted by brainwashed Nathaniel Hawthorne. Nathaniel shoots Sigma and Atsushi tries to save him again. However, Sigma excepts his fate and lets himself fall.

Before Sigma's demise, He used his Information Exchanging Ability on Atsushi and gave him info about the page's location. Atsushi learns that the page is currently held by the Decay of the Angel's leader, Kamui. At the same time, Kamui is taking the members of the detective agency out one by one by. Gogol saves Sigma from falling which shocks Sigma considering that Gogol was to supposedly die during the hostage incident. Gogol reveals that he intended on dying but before their plans took action, Fyodor's words moved him and then decided to kill Fyodor to be free. When Kamui takes Fukuzawa to the roof of a building, Kamui is revealed to be Ranpo. After the hostage incident, Ranpo laide low and uncovered the enemy's assassination plot against the agency in the meantime, hence saving the other agency members. Later in the evening, a preconference took place and Ranpo appears there, he shows a video of what really happened during the hostage plot. Ranpo show more proof of their innocents after the video was over. After showing the evidence, he further reveals that a certain page alters reality making the agency appear as terrorist and that no law enforcers will believe their innocent. Ranpo is then taken away by military police but is rescued by Minoura. The police force has been divided - causing the city police to protect Ranpo. The next day at the U.N. special headquarters located on Standard Island, Hunting Dogs captain Ōchi Fukuchi addresses the councilmen regarding the formation of the anti-terror group he calls the Army of Mankind. After the conference, Ranpo confronts him and asks for his help in defeating the Decay of the Angel. Fukuchi and Ranpo meat up with Atsushi on a ship and Ranpo deduces who Kamui is. After deducing who Kamui is, Ranpo is shocked learning that Fukuchi is Kamui and escapes by transport himself in Poe's novel. Atsushi makes a stand and gets ready to fight Fukuchi but is outmatched by his ability. Ryūnosuke Akutagawa comes to Atsushi's aid and the two of them fight Fukuchi together, only for Fukuchi to overpower them both with his space time sword, Shintō Amenogozen. Fukuchi then slashes Akutagawa but Atsushi manages to escape due to Akutagawa's sacrifice.

After his battle with Atsushi and Akutagawa, Fukuchi brings out a coffin that's holding Bram Stoker, the 5th and final member of the Decay of the Angel. He turns Akutagawa into a vampire and has half of the Port Mafia turned into vampires. Fukuchi's plan enters the final stage, turning half of the world's people into vampires and the Armed Detective Agency discus their plan on stopping him from obtaining the ability weapon called One Order at the airport. Meanwhile, Dazai and Fyodor play a deadly escape game at Meursault orchestrated by Gogol.