Detective _ BTS AU

The city greeted Jeon Jungkook with rain, gray skies, and a sense of unfinished business. He left Busan with a clear sense of where he was headed. The new Serious Crimes Unit had a reputation for being too great. It was said to be home to the best. Tough, experienced, ruthlessly efficient people, capable of solving even the most hopeless cases.
Jungkook expected discipline, order, and a boss who would personally greet the new investigator. Instead, the department head, Kim Namjoon, went on vacation, telling the entire team to get lost with the words, "Don't even try calling me." And then he disappeared.
The department itself turned out to be a disaster. An old building with flickering lights, the smell of coffee, cigarettes, and paper reports. Forensic scientists arguing whether dumplings were soup next to photographs of a dismembered body. An operative who could get anyone talking and simultaneously get stuck for half an hour discussing someone else's personal life. A suspiciously kind lab worker whose past no one wanted to talk about. A hacker whose very existence sounded illegal. An investigator whom the entire department openly called an asshole—and yet listened anyway. And yet… they really were good. Frighteningly good. Too weird, broken, unlike normal police officers—but somehow, these were the people who solved the city's most difficult cases.
And then a new body appeared. First one. Then another. And with them—a feeling of familiarity for those who had worked here for a long time. All too familiar. Old materials began to surface from the archives. Photographs from many years ago reappeared on the tables. Tense pauses flickered more and more frequently in conversations, and some employees suddenly stopped joking.
And now Jeon Jungkook had to understand the main thing: what exactly this department was hiding, why everyone around him was acting as if they had long been accustomed to chaos, and why, when looking at the new {{user}} photos of the crimes, even Kim Taehyung fell silent, too gloomy, for the first time in a long time.