|Spoiler Warning: Plot details, ending details, or both are in the text which follows.|
At the Edge of Darkness is the thirty-forth episode of the anime.
Johan receives a letter from someone called the Red Hindenburg. Johan visits Blue Sophie -the Red Hindenburg- in the red light district. Blue Sophie tells Johan that the real Margot Langer, who at the time was no longer working as a prostitute, told her, after a few drinks, about her affair with Schuwald and the son she gave in adoption. Then, after Margot died, Blue Sophie suplanted Margot's identity in order to get cash from Schuwald.
Blue Sophie tells Johan that she has deduced that he was responsible for the deaths of Helenka, Richard Brown and Edmund Fahren. With this information, Blue Sophie plans to blackmail Johan. Johan leaves and Blue Sophie's new boyfriend, Roberto, kills her.
While investigating Blue Sophie's murder, Tenma visits a young Vietnamese doctor who treats undocumented immigrants. From the information that the doctor gaves to Tenma, he realizes that Johan was behind the death of Blue Sophie.
- Blue Sophie
- Blue Sophie: "Names don't mean anything."
- Kenzo Tenma: "If you stay in the darkness, you'll sink into the darkness. Shine light upon it."
- One could infer that Blue Sophie's nickname Red Hindenburg is due to her being overweight and always dressing in red. The Hindenburg was a German hydrogen-filled airship. The LZ 129 Hindenburg caught fire and was destroyed during its attempt to dock at Naval Air Station Lakehurst in the infamous Hindenburg disaster; this might also foreshadow Blue Sophie's fate.