Chapter 54

The Perfect Murder, The Perfect Killer, Part 1 (完璧な殺人と殺人者 其の壱,) is the 54th chapter of the Bungo Stray Dogs manga.

Summary
Mushitaro Oguri is killing someone with a shovel. Meanwhile, Ranpo, in a bear costume, visits the imprisoned Kunikida. He says that the latter has been framed by Dostoevsky and that he will prove Kunikida innocent. When Ranpo runs back, he crashes into Poe, who is reading a mystery magazine at the moment, wondering what the solution could be. Ranpo removes the head of his costume and explains that he has to wear a bear costume to help a local shop owner as a part of his punishment for ignoring the President's orders not to attack the mafia.

The two head to the windows, while Ranpo tells Poe of his suspicions that there might be a "Cleaner" for the Rats and that he owes said Cleaner due to the fake police data that tricked him. Hence, the Cleaner knows Ranpo's face and vice versa, compelling Poe to search for the Cleaner without Ranpo's physical help. Poe initially doesn't think much about the case but realizes there's something to Ranpo that forces him to work together.

Not getting any further, Poe starts talking about the mystery in the magazine. He says that it was the author himself who died before the fourth and last chapter could be released. The method was the same as in the writer's stories. The killer apparently took the manuscript because the trick to the murder was revealed in the fourth chapter. Many people have tried solving this but came up empty. Poe had been thinking of it but didn't solve it yet, after which Ranpo remarks that Poe must have a lot of free time.

When Ranpo takes a look at the magazine, he says he figured out the murderer in a few seconds. He also says that the murderer had two motives: resentment and money. According to Ranpo, the murderer was close to the author and was waiting for the fourth chapter to finish so it could be illegally sold after they had killed the author, specifically to Poe.

Yielding to Ranpo's deduction, Poe informs him that he shall receive the manuscript from someone with a red envelope. Ranpo notices a red envelope perched near the window, and the two take it with an instruction on the window to look up. At that moment, they see a man fall off the tower to his death. Poe recalls the man's face to be the Cleaner, at which Ranpo considers the red envelope to be a crucial item.

They rush down to the Cleaner's body, after which they encounter Minoura and his companion arrive at the scene. Ranpo excitedly rushes to Minoura, which Poe tries to deduce the reason behind it. Ranpo proceeds to tell him that the criminal has notified the police before the man fell off, indicating that it was not suicide. Moreover, Ranpo and Poe check the victim's shoe and deduce together that the victim is not the Cleaner, but he was rather killed by the Cleaner to camouflage himself.

Ranpo then brings out his glasses to find the criminal's location. Among the crowd, Mushitaro revels how things are unfolding according to plan, afterwards activating his ability, The Perfect Crime, that erases evidence in crimes. Ranpo then turns to his companions, stating that he cannot find anything. Mushitaro becomes thrilled at Ranpo's defeat, which would deter him from defending Kunikida's innocence and figuring out the motive behind Fyodor's surrender.