The cast of "Flex X Cop 2" made a successful variety show debut.

On the August 2 episode of SBS "Running Man", the members formed teams with the cast of the drama "Flex X Cop 2" for an "Undercover Chaebol VS Detectives" race.

In this episode, Yu Jae-seok formed the chaebol team with Jee Seokjin, HAHA, Song Jihyo, Ahn Bo-hyun, and Kang Sang-jun. Meanwhile, Kim Jong-kook formed the detective team with Yang Sechan, Ji Ye-eun, Jung Eun-chae, and Kim Shin-bi.

Hidden within the chaebol team were one secret chairman and one secret agent, while the detective team included one undercover secretary dispatched by the chairman. The chaebol team would win if the chairman escaped with only the chaebols, excluding the secret agent, whereas the detective team had to find the undercover secretary and the chairman.

After gathering hints through various missions, the chaebols and detectives made their moves. Jee Seokjin secretly approached detective team member Kim Jong-kook and revealed that he figured out who the chairman was, stating that HAHA was the chairman. When Kim Jong-kook asked, "Are you then the secret agent, hyung?", Jee Seokjin answered yes, drawing attention.

Tasked as the secret agent, Jee Seokjin had been subtly sabotaging the chaebol team's missions while carrying out his mission. Through the crucial hint obtained along the way, he figured out that HAHA was the chairman.

At the same time, the chairman, HAHA, was solving quiz questions with chaebol Yu Jae-seok to find the password for the money bag. HAHA failed to get a single question right, but secured the password thanks to Yu Jae-seok's efforts. Coincidentally, the password turned out to be Yu Jae-seok's birthday. HAHA complained, "Why is the password this when I'm the chairman?", to which Yu Jae-seok cracked everyone up by seeing right through the production team, saying, "Did you assume I would solve the questions anyway?"

HAHA instructed Yu Jae-seok, "I'll get in the car and start the engine, so you gather the people." The two agreed that Ahn Bo-hyun must be the secret agent and decided to leave him behind.

Yu Jae-seok went to gather the other chaebol members, but during the process, Jee Seokjin's suspicious behavior made Yu Jae-seok suspect him as well. In response, Jee Seokjin insisted he was definitely not the one and claimed that Ahn Bo-hyun was the spy.

Meanwhile, the detective team operated under the assumption that Yang Sechan was the undercover secretary, excluding him from their movements.

As the chaebol team hurriedly attempted to escape, Ahn Bo-hyun spotted the scene and rushed to follow them. Seeing this, HAHA and Jee Seokjin insisted that Ahn Bo-hyun was a detective and strictly blocked him from getting into the car.

Just then, Song Jihyo appeared and stated that Ahn Bo-hyun was not a detective. Song Jihyo drew attention by saying, "My hint says the police officer is not Bohyun. The secret police officer is married."

Convinced that Jee Seokjin was the secret agent, the chaebols confronted him. Jee Seokjin protested, asking, "What does married have to do with this?" However, the chaebols dragged him out by force and succeeded in escaping.

With the chaebol team's final victory, the detective team faced a full-group penalty. However, if they accurately found the undercover secretary, only two members of the detective team would receive the penalty. Having suspected Yang Sechan, the detectives changed their minds right before voting and suspected Ji Ye-eun instead. Thus, the detectives ultimately pointed to Ji Ye-eun. However, the real undercover secretary was revealed to be Jung Eun-chae, surprising everyone.