Episode 1 recap: Lin Mo sneaked into the mental hospital.

Lin Mo is a detective and the apprentice of Tang Ren, a famous detective in Chinatown. In order to facilitate his investigations, he deliberately lived near the detective agency. There is a girl who has fallen for him, and following the principle of "to catch a man's heart, you must first catch his stomach," she went to two restaurants and bought two dishes for Lin Mo. With just a sniff, Lin Mo guessed what dishes were inside the boxes, and he accurately identified which restaurant each dish was from.

Meanwhile, Tang Ren was flirting with girls in Chinatown when pianist Da Bang suddenly approached him. Da Bang is also a detective, and he discovered something suspicious at the Angel Retreat, a sanatorium. He came to Tang Ren for help, but what surprised Tang Ren was that Da Bang didn't want him to go to the Angel Retreat, but instead wanted his apprentice, Lin Mo, to go there.

While Lin Mo was enjoying the meal sent by his girlfriend, he received a call from his master, who explained the situation and asked him to go to a piano store. Later, Lin Mo received a call from Da Bang, who introduced himself and only sang him a song before hanging up. Lin Mo and his girlfriend went together to the piano store, where Lin Mo learned that it was Da Bang's store. Da Bang is wealthy and, like the famous detective Hayabusa Nitta, treats solving cases as a hobby.

Inside Da Bang's piano store, a girl was playing the piano. After Lin Mo and his girlfriend explained their purpose, the girl asked them to repeat the song Da Bang had sung. She then informed them that Da Bang meant for Lin Mo to go to the Angel Retreat's bathhouse at midnight. Lin Mo had some knowledge about the Angel Retreat, as a detective had previously tried to enter for evidence but was denied access.

To enter the Angel Retreat, one must pose as a mental patient. Just as Lin Mo raised this question, the girl presented prepared files. Da Bang had already prepared a case for him before Lin Mo's arrival. Accompanied by his girlfriend, Lin Mo arrived at the Angel Retreat. Without any reminder from his girlfriend, Lin Mo put on a show, his eyes becoming vacant and clearly exhibiting signs of a mental patient. Nurse Peng Xi, who greeted them, glanced at Lin Mo and then informed them that Lin Mo's code name is 414. Visiting hours are on the 15th and 30th of each month, and during that time, it's best not to disturb the patients. After speaking, Peng Xi opened the iron door where the mental patients were held, led Lin Mo inside, and advised him to get along well with the other patients.

Inside a large house, crowded with mental patients, some were crying, some were laughing, and some were speaking incoherently, creating a chilling atmosphere. Lin Mo noticed a young man playing the piano and thought he seemed somewhat normal, so he approached him and asked if he knew the pianist. However, the young man told Lin Mo that he himself was the pianist. Lin Mo mentioned Da Bang's name, but the young man shook his head, indicating that he didn't know him.

Just then, someone voluntarily approached Lin Mo and told him that they knew where Da Bang was. Excitedly, Lin Mo followed them and arrived at a pillar in the corridor. The person began hitting their head against the pillar, telling Lin Mo that if they hit it a few more times, they would be able to see Da Bang. Realizing that he was being deceived, Lin Mo decided to search on his own. However, every few steps he took, a bearded man approached him with clear malevolence. Fortunately, Peng Xi arrived and pulled Lin Mo aside, quietly informing him that the man was called Shama, a former Taekwondo champion, and it would be best for Lin Mo to stay away from him.

Peng Xi led Lin Mo to her own room. At midnight, Lin Mo sneaked into the bathroom and unexpectedly discovered Da Bang hanging there, having been dead for some time. Lin Mo examined the body and found signs of strangulation before the staged hanging to simulate suicide. There were also traces of dragging on a patterned steel plate on Da Bang's body, and a flower character written in the palm of his hand.

Upon seeing this, Lin Mo quickly sounded the alarm and revealed his identity to the superintendent who arrived later, urging him to call the police immediately. However, the superintendent ignored his plea. In desperation, Lin Mo attempted to escape while they were distracted, but he was grabbed by Shama, who forcefully pinned him to the ground.