is the title of the fifth episode of Season 4, which concludes the mystery involving the writer Yokomizo and his friend Mushitaro Oguri . Key Plot Summary

Ranpo convinces Oguri to turn himself in by threatening to expose the truth—that the murder was a farce born of friendship—which would ruin the author's final wish for a "perfect mystery" .

Ranpo promises to find Oguri a job within the government's special division once he is released . Climactic Twist

It is revealed that the murder was actually a "assisted suicide"; the author, suffering from terminal cancer, wished to create the perfect final mystery and asked his friend Oguri to kill him .

The episode follows as he deduces that Mushitaro Oguri is the perpetrator behind the "mystery writer murders" .