Episode 55

At the Port in the Sky (Part 1) (空ノ港ニテ（其の一）,) is the 55th episode of Bungo Stray Dogs anime series and the fifth episode of the fifth season.

Synopsis
The Detective Agency races to stop Fukuchi from receiving the One Order, a devastating mind control weapon that will make his plans for world domination unstoppable.

Summary
With the Agency's key members back together, they convene on their current situation of the Decay's final phase of global vampire contagion. They deduce that various armies comprising dormant vampires turned from Bram's ability can further grow in number once they infect others in silence. Ranpo and Fukuzawa tell them of the enemy's true objective: One Order, a sealed ability weapon that can ensure a commander's subordinates to follow their orders.

Should Fukuchi acquire and use the weapon, Ranpo surmises that he shall place the Army of Mankind under his command to fight the vampires. In essence, he concludes the Decay's ultimate goal to be world domination. The great detective then explains his plan of how to stop Fukuchi's retrieval of One Order within 12 hours at the airport.

At the location, Aya—dubious of the allegations against the Agency—encounters the Hunting Dogs anticipating the Agency for their attempt to intercept One Order's delivery. Jōno takes notice of her and menacingly threatens to make her a hostage to bait the Agency, until Tetchō thwarts him. Before the two can escalate their squabble, Fukuchi arrives and takes Jōno to Bram's coffin, then reveals himself as the true mastermind that Tachihara previously suspected.

Having recruited Jōno in the past for the sake of his present plans and given Jōno's distinct character, Fukuchi invites him to join the Decay. He tasks him to kill the Agency to prevent them from killing Bram, which Jōno accepts. However, once Fukuchi lets his guard down, Jōno attacks him from behind and claims that he chooses to protect others rather than revel in their pain.

Betrayed by another subordinate, Fukuchi summons Amenogozen and turns back time, stopping Jōno's surprise attack on him. Jōno activates his disintegration ability to battle Fukuchi but is overpowered by Akutagawa's arrival and Fukuchi's prowess. Akutagawa bites and incapacitates Jōno, though he warns Fukuchi that he, too, shall taste his own suffering; he has tipped Aya earlier, who witnesses Fukuchi's revelation and involvement in the entire incident.

Aya resolves to expose Fukuchi by taking a photograph as evidence, but her phone captures the image with a flash, rousing Fukuchi's suspicion. Aya panickally manages to evade him but soon runs out of hiding areas, but she eventually thinks of one possible spot. Fukuchi then slashes through a locker where the witness can hide in, only to find nobody.

Manga and Anime Differences

 * The anime simplifies the reunion of the Agency's key members:
 * It omits the scene where Atsushi remarks on Kunikida's collected demeanor and Kunikida's mention of having wept earlier for two hours.
 * While the manga shows Tanizaki and Kenji hiding and getting caught by Kyōka and Demon Snow at the Agency meeting, having been contacted by Mori to regroup with the other Agency key members, the episode only shows that the two have already returned ostensibly offscreen.
 * As a minor difference, Ranpo is shown eating popcorn and later lollipop in the manga while explaining the Decay's plan, but he does not in the anime.
 * The British-German-French Joint Base in the South Pole where One Order is sealed is named in the anime as the British-French Joint Base.
 * In the manga, when Fukuchi regroups with the Hunting Dogs at the airport, Jōno questions where he was, and Teruko notes that he appears tenser than usual. This episode omits these remarks.
 * At their airport hideout, the manga illustrates Atsushi turning delighted when Ranpo praises his retort, though the anime does not include this reaction.
 * The manga briefly depicts Jōno as a past crime ring leader, which is omitted in this episode.
 * The anime does not explain that Jōno's disintegration ability allowed him to slip into the Agency's runaway car at the onset of the terrorism incident.
 * In the manga, while Jōno is being taken away by Akutagawa, he further ponders and laughs on Fukuchi's possible downfall, though this is omitted in this episode.