13 timestamped notes explaining the Korean cultural context in this episode — customs, idioms, food, honorifics, and history, at the moment each appears on screen. These notes discuss events across the whole episode. To see them revealed scene-by-scene as you watch, use the episode page to find an airing.
The radio call reporting an unidentified body (신원미상 변사체, shin-won-mi-sang byeon-sa-che) follows a standard Korean police dispatch format — the officer on the other end responds '순 하나, 출동합니다,' meaning 'Unit one, responding.' Korean patrol units are numbered this way, much like '1-Adam-12' in American police shows.
The doctor references a prior diagnosis of 알콜 의존증 (alcohol dependence) from six years ago. In Korea, alcohol-related disorders have historically been under-reported and under-treated due to social stigma, and denial — as shown here — is extremely common, especially among older generations who see heavy drinking as culturally normal.
Dong-eun is having her mother committed against her will. Under Korean law (정신건강복지법), a person can be involuntarily admitted to a psychiatric facility if a family member requests it and two psychiatrists agree the person poses a risk. Being the sole blood relative (유일한 핏줄, yuilhan pitkkeul) gives Dong-eun the legal standing to make this call alone.
The landlady laughs that a 월세방 (wol-se-bang) — a basic monthly-rent room, the most affordable tier of Korean rental housing — is getting a luxury Bauhaus makeover. In Korea's rental system, 월세 sits below the larger lump-sum deposit system called 전세, so it signals Yeo-jeong is fixing up a genuinely modest space.
The reporters surrounding Sa-ra are performing a 취재 공세 — an aggressive press ambush typical outside Korean courthouses and police stations. Journalists shout questions simultaneously and thrust microphones forward; the target is expected to walk through without stopping. Answering even one question is seen as an invitation for more, so most PR handlers coach complete silence.
In the flashback, young Sa-ra uses the slang 짱친 (jjang-chin), a contraction of 짱 (the best) and 친구 (friend). It was the go-to word for a closest best friend among Korean teens in the 2000s–2010s, roughly equivalent to 'bestie.' Hearing it from their school days underlines how long this toxic friendship has lasted.
Jae-jun reveals that Myeong-o's body was found at the same derelict rooftop where Yun So-hui fell years ago. In Korean crime dramas and in real investigations, returning to a 폐건물 (pye-geonmul, abandoned building) links crimes across time. The detail that the same spot claimed two victims is meant to read as no coincidence to a Korean audience.
Jae-jun quips that Do-yeong prefers to '매도 먼저 맞다' — literally 'get the beating first.' It's a well-known Korean proverb meaning that if something unpleasant is unavoidable, it's better to face it head-on than drag it out. Using it here is darkly ironic, given what Jae-jun is about to reveal.
Yeong-jun describes himself and the other man as 불알친구 (bul-al-chin-gu) — literally 'testicle friends,' meaning they've known each other since they were small boys running around without clothes. It's a very common, affectionate (and crude) expression for a decades-long male friendship, the kind where both men have dirt on each other.
The woman Seok-jae meets is a 무당 (mu-dang), a Korean mudang or shaman who performs 굿 (gut) rituals to communicate with spirits and resolve misfortune. Her workspace is a 신당 (shin-dang), a spirit shrine typically filled with colourful deity paintings, candles, and offerings. Wealthy Seoul families consulting mudangs — often in secrecy — is a well-documented real-world phenomenon despite Korea's modern image.
Lighting candles and slaughtering a chicken to drain its blood are standard opening steps of a 굿 ritual. The blood is believed to appease or drive away malevolent spirits. Full 굿 ceremonies can last all night and involve elaborate costumed dances, drum music, and offerings of food and drink — the 'big 굿' mentioned by the assistant confirms something major is being prepared.
Dong-eun asks whether a lighter found at So-hui's scene could carry DNA. In Korean forensic practice, the 국과수 (Gukgwasu — National Forensic Service) handles this testing. Saliva or skin cells left on a lighter's flint wheel or mouthpiece can be enough for a DNA profile. The 국과수 reference at the very end of the episode confirms this is exactly where the detective is headed.
In the flashback call, Yeong-ae immediately tells teenage Yeon-jin to expect a call from '신 서장 아저씨' — Chief Shin, addressed as 'uncle,' a polite Korean term for a family friend of the parents' generation. Casually phoning a police chief to manage an incident is a sharp shorthand for how elite Korean families have historically used 연줄 (personal connections) to stay above the law.