Gereon interrogates Johan König who had been tortured by a mysterious man before the interrogation. He gets hold of the inspector's gun and at first appears to wants shoot Gereon, but Johann instead turns the gun on himself and commits suicide. This triggers Gereons PTSD, so he rushes to a nearby bathroom to take some morphine, but is unable to do so because of his heavy trembling. Charlotte, who is in the neighboring stall, finds him and helps him take his drugs. After this incident, Gereon phones with his father who is disappointed that the film has not been found yet and urges his son to destroy it should it reappear.
A short time later Gereon and Bruno get called into August Benda's office. He is the head of the police and asks them why König was heavily injured after Bruno's interrogation, but neither of them tell the truth. Benda has a private conversation with Gereon and asks him why he got transferred. Gereon admits that his friend, the mayor of Cologne, was blackmailed with a film that is said to be in Berlin. He asked Gereon to find it before the upcoming elections. Gereon looks for and finds Krajewski who can't tell him anything about the film.
At night, Charlotte visits the Moka Efti, a popular variety theater. She listens to a singer called Nikoros, who is actually Svetlana in disguise. Charlotte follows one of the patrons to the club's basement which houses a brothel, and it is revealed that she has a second job there as a prostitute. Svetlana's fellow trotskyists at the print shop get killed by the same men who ambushed the train, but they miss Kardakov who had hidden in the lavatories.
Tropes:
- And Then What?: When König steals Gereon's sidearm during his interrogation of him, and holds him at gunpoint, Gereon just calmly asks him this, pointing out that even if he shoots him, he is still right in the middle the largest police station in Germany, and likely won't get out alive if he does so. As it turns out, Gereon is wrong about what König is planning to do...
- Better to Die than Be Killed: König kills himself with Gereon's weapon as he feared A Fate Worse Than Death by the hands of Armenian because He Knows Too Much.
- Brick Joke: After Gereon leaves, the pharmacist browses his new photographs, and is disturbed to find one of severed arms mixed in.
- Chekhov's Gun: The case of laudanum that bounces behind the toilet and gets stuck in a crevice in the wall.
- Cock Fight: During Nikoros' musical number at the Moka Efto, Jaenicke takes an opportunity to butt in next to Charlotte, and Rudi and Jaenicke engage in peacocking via dance in an attempt to win over Charlotte.
- The Can Kicked Him: Inverted. Kardakov only survives the massacre against the trotskyists because he goes on a luckily timed visit to the outhouse.
- The Corpse Stops Here: A guard sees Gereon holding König's body after the latter killed himself, making it look like Gereon killed the suspect. But thanks to Benda the messy incident gets swept under the rug.
- Make Sure He's Dead: The Soviet hitmen execute any surviving Trotskyists with headshots.
- Montage Out: The second-to-last scene is a montage sequence of parallel events. A raving jazz number plays while we see the shooting at the printing shop, dancing people at the Moka Efti, Charlotte with a patron at the brothel and Nikoros changing into Svetlana at her dressing room.
- Not His Blood: In the bathroom Charlotte sees Gereon with König's blood on him which worries her. He notes that it's not his blood.
- O.O.C. Is Serious Business: After the "visit" by Saint Josef and during Gereon's interrogation, the previously defiant and combative König is reduced to a jittery, panicked shell. Gereon notes as much while discussing the incident with Benda, saying that he was a "stuck-up, arrogant guy...until this morning," indicating that König was in deep with some very dangerous people and hence that the investigation might go deeper than they anticipated.
- Outdated Name: Lampshaded, when Gereon introduces himself to Charlotte. She asks him what kind of name "Gereon" is, joking that he must come from the middle ages. Gereon smirks a bit as he replies that he is actually from Köln.
- The Purge: The Soviet hitmen massacring the Trotskyists in the printing shop.
- Sole Survivor: Kardakov swimming in the sewage below the outhouse.
- You Must Be Cold: At the printing shop, Kardakov hands a coughing young Trotskyist his coat noting that he will soon be in Istanbul where he wouldn't need it anyway. The coat transfer becomes a plot point in season 2.
