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 killer narrates his thoughts in formal, almost literary Korean — using older vocabulary like 사냥감 (sa-nyang-gam, 'prey') and 숨골이 끊어지다 ('the breath-knot is cut'). This elevated, detached register is a classic storytelling device in Korean crime fiction to signal a calculating, cold mind rather than impulsive violence.
Korea has a long history of quasi-religious groups — some legitimate, some controversial — running factories, farms, or schools as part of their community programmes. When a building is described as 종교 단체 운영 (jonggyo danche woolyeong, 'run by a religious organisation'), Korean viewers immediately read it as shorthand for a potentially cult-like group, adding an extra layer of unease to the abandoned site.
The woman teases that the grandmother would rush out to watch even a 모깃불 (mogitbul, a mosquito-repellent coil fire) if someone called it an emergency. This affectionate jab reflects the tight, face-to-face social fabric of older Korean residential blocks, where neighbours genuinely knew each other's daily habits — something rapidly disappearing in high-rise apartment complexes.
The joke about '한서준 3세 (Han Seo-jun the Third)' plays on the Korean practice of children almost always taking the father's surname. Imagining a son of Han Seo-jun would carry that exact name and identity — especially the name of a notorious serial killer — makes the prospect feel horrifying rather than dynastic.
Korea has one of the world's densest public CCTV networks in urban areas, so police routinely start investigations by pulling footage from subway stations, buses, and street cameras. The detectives' immediate instinct to check 구동역 (Gudong Station) cameras is standard procedure — which makes the gap caused by the abandoned redevelopment zone feel like a genuine dead-end rather than a plot convenience.
The shop owner panics that cooperating with police could expose that he employs 불법 체류자 (bulbeop cheryuja, undocumented migrants). Small businesses in Korea — particularly food stalls and factories — sometimes hire workers without proper visas, and the fear of a labour inspection often silences potential witnesses, a real barrier that Korean investigators face.
막걸리 is a milky, lightly fizzy rice wine — Korea's oldest alcoholic drink, historically beloved by working-class and rural communities. For older grandmothers it carries the same warm, everyday comfort as a cup of tea might elsewhere. The revelation that the usually proper-seeming grandmother secretly loved it is a small, humanising detail that makes the grief land harder.
보쌈 is a classic Korean dish of boiled pork belly, usually served with kimchi and wrapped in salted napa cabbage leaves. It is the kind of hearty, hands-on meal Koreans associate with home cooking and celebrations. Offering to make it is the ajumma's (older woman's) language for 'I want to take care of you' — food as emotional support is deeply embedded in Korean culture.
The profiler references the real American serial killer Dennis Rader, who called himself BTK — short for Bind, Torture, Kill. Rader murdered at least ten people in Kansas between 1974 and 1991 and was caught in 2005 after sending a floppy disk to a TV station that was traced back to his church. His case is frequently cited in Korean crime dramas and true-crime media as the textbook example of a killer whose craving for attention led to his downfall.
잡채 — glass noodles stir-fried with vegetables and beef — is one of Korea's most labour-intensive home dishes, traditionally made for birthdays and holidays. Preparing a huge batch because a grown man loved it as a child, then hiding who made it so he will actually eat it, is quintessentially Korean mother energy: love expressed through food and quiet self-effacement rather than direct affection.
Telling someone to quit and become a chef instead — 적성에 안 맞아 보인다 ('you don't seem suited to this') — is a distinctly Korean form of backhanded praise. Korea places enormous cultural weight on finding your 적성 (jeokseong, innate aptitude or calling), and redirecting someone toward their obvious talent is considered genuine encouragement, even when it comes out sounding like an insult.
셜록 홍주 (Sherlock Hong-ju) is a fictional investigative current-affairs programme styled after real Korean 시사 교양 shows — serious, prime-time, live broadcasts that tackle crime, social issues, and investigations. These shows have massive audiences and cultural authority in Korea, which is why the killer chose it as his stage: a live national platform is the ultimate act of 과시 (gwasi, showing off).
Korean broadcasters are required by the Korea Communications Standards Commission to display on-screen warnings before content unsuitable for certain viewers — 미성년자 (minors) and 심신미약자 (people with diminished mental capacity) are the standard legal categories. Hearing this warning in the middle of a live special broadcast signals to Korean viewers that something genuinely disturbing is about to be shown, not just dramatic filler.