Episode 4 recap begins with vice president Hwang firing Cha-il, but Cha-il still pushes for the director’s audit, ignoring vice president Hwang’s orders. He meets up with Han soo who has blocked Ms Yoo’s car, preventing her from leaving.
Vice president Hwang learns from director Yang that Ms yoo voluntarily went to the police station. He then goes to the president, telling him that Cha Il went against his orders but the president replies that he gave him authority over the audit department but he wasn’t given the power to fire Cha-il. Vice president Hwang’s threat to stop the construction doesn’t work because the president knows he won’t actually stop it since the deal has already been signed.
Han soo returns to the office and tells everyone the progress of the situation. Yeom kyung suk doesn’t think Cha il will get the money back but Han soo strongly believes in him.
At the office, Seo-jin faces a dilemma: should she help her uncle or the old resident and many others who have lost everything due to the embezzlement?
While Cha IL driving Ms Yoo to the station, she mocks him saying he will be fired if he doesn’t provide the money. Cha il doesn’t care about that saying he will only be punished whereas she would live a terrible life in jail.
The audit team eats lunch at the cafeteria except for seo jin. There, Yeom once again bad-mouths Cha il claiming that no one wants to eat with them because they have made many enemies. However, Han soo counters him saying auditing people is not enough reason for them to be hated.
Elsewhere, Ms Yoo is later released with Hwang’s help while the union president takes all the blame. She boasts to Cha il saying that he has always been idealistic. As she leaves, Shin Cha-il calls vice president Hwang and strikes a deal with him. If he cancels Mi-kyung’s Florida transfer, Cha-il will take the blame for the 3.4 million dollars and pay the amount himself if he cannot find the money within three days. Cha il then calls Han soo to enlist him and Seo jin’s assistance in finding the money. Han soo then meets a burdened Seo jin bringing with him a packed meal as he tries to cheer her up telling her that it’s up to them to find the missing money now.
Cha-il then visits Ms Yoo’s husband Kang Myung-Chul, who’s also an auditor in his construction company. He finds him holding a professional lecture on morality and afterwards ask him about the money but he acts clueless. Cha Il threatens him that a person who pretends to be good would soon be exposed but he doesn’t care and leaves. Vice president Hwang meets with Ms Yoo at a park and he tells her that her transfer has been canceled because he has given Cha il three days to find the money. He warns her to hide the money well for that period of time.
During a meeting with his staff, Cha il tells them to look into Myung chul’s construction company but Seo jin surprisingly seems to be against it. However, Cha il announces that he will take responsibility. Han soo is surprised by Seo Jin’s change of heart. He is so bothered that he even texts her, asking if president Hwang threatened her but Seo Jin is unable to tell him the truth. However, he becomes happy when she agrees to follow him to the construction site.
Together, Han-soo and Seo-jin interview the workers of Myung-chul’s construction company to trace the money, believing that Myung-chul would launder it to avoid detection but it’s Han soo doing all the work while Seo jin just watches him.
Cha il follows Myung chul to a judo house and once again asks him about the money but Myung Chul threatens to take action against him if he sees him again.
From Han soo’s investigation, the team discovers that the workers at Myung Chul’s company were paid in cash briefly before switching to bank transfers. It’s later revealed that Kang Myung-Chul switched the embezzled cash with marks on them with his company’s cash through the help of finance team employee, Lee Yeon-Ji, who he is probably having an affair with because Cha il recalled that while discussing with Myung chul at the judo place, she had called him. The embezzled cash was then used by the workers and eventually scattered, becoming untraceable. He suggests they should check their social media accounts to determine if they have a secret relationship.
Director Yang tells vice president Hwang that Cha il must have figured out how the money was laundered but thankfully, he hasn’t found the money yet. Han soo checks Lee yeon ji’s social media account and discovers Myung chul in her photo signifying that they are indeed lovers.
Vice president Hwang calls Cha il to get a report on the case but ends up lash out at him saying that he hates stubborn self reliant people like him. Just as he’s about to go on, Cha il cuts him off by answering a call. After wards he asks Vice president Hwang if he has anything else to say and leaves with vice president Hwang yelling that he will crush him.
Han soo shows Cha il the photo of lee yeon ji and Myung Chul. Cha il wants something more concrete and orders Han soo to trach lee yeon ji. When Shin Cha-il meets Ms yoo again, he shows her a picture proving her husband’s affair. She refuses to believe it. Later as he drives away, Cha-il is threatened by two trucks trying to run into his car but he speeds off and escapes. He then calls Han soo and seo jin telling them to be careful since he was almost killed. Meanwhile, Han-soo and Seo-jin are shadowing Kang Myung-Chul and Lee Yeon-Ji, discovering they were behind the truck threat after the drivers meet up with them. However, they are nearly caught by Myung chul but manage to escape.
Myung chul and Ji yeon go to a motel. Ms yoo calls him but he is cold towards her as he assures her of their scam working. However, Ms yoo hears Le yeon ji’s voice. Turns out she is also talking to her own husband on phone. Meanwhile, Han soo and Seo jin take pictures of the two in front of a motel. Cha il meets up with them in front of the motel and Han soo, worried immediately asks after his well being before showing him the photos.
On her way home, Seo jin is in a dilemma, unsure of how to proceed or which side to choose.
The next day, the audit team is unable to reach Ms yoo because vice president Hwang had her confined in a hotel without her phone. After searching for her for a while, just when Cha-il is feeling disillusioned, he suddenly receives an anonymous tip regarding her location. He’s finally able to show Ms Yoo proof that her husband is cheating on her and possibly plans to leave with Yeon-jin and the money, dumping the entire blame on Ms Yoo. He tells her that from their university days, she was warm dignified woman with dreams. He can’t understand what has suddenly happened to her. Ms Yoo is devastated.
Shin Cha-il informs the team that Kang Myung-Chul laundered the money and fabricated sources of funds by purchasing and reselling construction vehicles. They need to find the documents as evidence and head to his fake company’s address. Han-soo and Seo-jin reach the location, but Seo jin is reluctant until Han soo tells her about the old resident getting sick and his grand children caring for him. She finally follows him and just as they find the documents, with Han soo nearly risking his life, Kang Myung-Chul, whose pictures with Yeon-ji have leaked to the staff at his company, takes the documents from Han-soo after attacking him. He knocks him out, and leaves.
After a long chase resulting in Han soo getting beaten up, Shin Cha-il finally finds Myung-Chul just as he is about to escape again. After defeating him in a fight, he reveals he doesn’t have the money and that Ms Yoo had tricked them both. However, Cha-il finds Mi-kyung at the airport and gets her arrested. The money is found in a car that had been parked in a parking lot.
Cha-il then reports to VP Hwang and the president that they have recovered the entire amount from the assets of those at fault. Vp is unhappy about it. President Hwang reveals to Cha IL that the tip about Ms Yoo’s location came him. This surpses Cha IL.
Han Soo offers to celebrate the win with Cha IL but he refuses telling him to celebrate on his own. He then asks Seo Jin to follow him to his parents restaurant but she too refuses, claiming to be busy.
Meanwhile, Cha IL visits Ms Yoo in prison. She reveals that she did that to get revenge on her husband but Cha IL doesn’t plan to go easy on her. She pleads with him to get her out but he tells her he is no longer a romantic and he would use her as an example to others not to betray people’s trust.
Han-soo celebrates the win with the old resident and his grandchildren at his parents’ restaurant. The grandchildren ask after Seo Jin and he responds that she is busy. The old resident reveals that the union president called him from jail apologising for stealing his money because of poverty. He forgave him which makes Han Soo surprised. Meanwhile, Seo-jin’s relationship with VP Hwang seems tense when she reveals to him in front of his house that she helped retrieve the union people’s money. She wants to know why he didn’t want them to find the money but Vp Hwang changes the conversation by inviting her home for a meal which she rejects before leaving.
The next day, Shin Cha-il receives a new case involving a threat where construction site workers fall ill after lunch, with the same threat looming over the company workers. The audit team then go to the cafeteria and Shin Cha IL tells the other employees to stop eating but no body hears him until he yells at the top of his lungs.
It’s interesting how the entire thing finally got resolved but how did the president know Ms Yoo’s whereabouts. He’s really a suspicious fellow.