Channel A's 'Detectives' Trade Secret' tracks the mysterious relationship between a groom-to-be and his female boss, who is 15 years his senior.

This episode features the story of a bride-to-be, a female civil servant working at a district office. A single photo posted in a company group chat was the beginning of the conflict. The photo showed a man and a woman embracing on a staircase, and the bride-to-be immediately recognized the man as her future husband.

The two grew close while working in the same department. The groom-to-be was raised by his grandmother and had stayed away from dating or social gatherings, but the bride-to-be's proactive courtship led to a romantic relationship, and they were preparing for marriage following news of her pregnancy.

However, a single photo turned everything upside down. According to the investigation by the detective team, the groom-to-be was captured being visited and persuaded at night by his boss, who is 15 years older.

In response, the groom-to-be clarified, 'The two are not romantically involved, and he only relied on his boss like a mother or an older sister.' He also claimed that when he tried to distance himself during the wedding preparations, the boss threatened to disadvantage him in promotions.

The cast could not hide their surprise. Yoo In-na said, 'I never imagined this,' and Defconn and Kim Poong were equally shocked by the startling truth.

Meanwhile, on this episode, Kim Min-soo of Pishik University appears as a guest detective. Kim Min-soo, the only unmarried member among Pishik University members, expressed envy toward his colleagues' married lives. He drew laughter by saying, 'My older colleagues only brag about how great married life is, but they never set me up with anyone.'

When Defconn mentioned Kim Ji-yoo and Park Se-mi, noting that Kim Min-soo had previously said his ideal type is someone funny, Kim Min-soo replied, 'We don't quite click,' and surprised everyone by naming another person as his ideal type.

'Detectives' Trade Secret' airs on Channel A on July 20 at 10 p.m.