Episode 4 of Lies Hidden in My Garden starts with Joo-ran throwing away the pills Jae-ho had given her. A flashback shows Joo-ran from the time she discovered her sister’s dead body. She recalls seeing a man who lived in the house next to where her sister, Young-ran, was found.
Years after that, Joo-ran recalls seeing the same man reappear in her life as her son. Someone who happens to be Seung-jae’s teacher. Joo-ran gets cynical after seeing him, telling Jae-ho that she was afraid the man was back in her life to harm her son. That night, Joo-ran finds herself rushing to the concert looking for Seung-jae.
Joo-ran believes the man is taking Seung-jae away and uses a log of wood from the bonfire to attack him. She is shocked when she learns that the boy is not Seung-jae.
Back to present-day, Joo-ran finds herself at her neighbour, Hae-soo’s, house asking for the CCTV footage from the night of Yoon-beom’s murder. She asks Hae-soo to keep their interaction a secret and leaves to go back to her own house.
The next day, Joo-ran goes to pay Sang-eun a visit. She heads into Sang-eun’s house and asks why she thought Jae-ho was responsible for the death of Yoon-beom and how she knew Jae-ho. Sang-eun shows Joo-ran the videos of Yoon-beom threatening people from the spare phone.
Another flashback shows Sang-eun going through Yoon-beom’s diary where it was mentioned that the pink spare phone belonged to a woman named Lee Soo-min. In his notes, Yoon-beom was trying to figure out the connection between a sex worker called Soo-min and Jae-ho. She recalls how Yoon-beom was looking to extort 500 million won from Jae-ho in exchange for the information that he was behind a prostitution ring.
Present-day Joo-ran goes through the images and videos on the spare phone but denies Jae-ho’s involvement in anything related to prostitution. Sang-eun asks Joo-ran to talk to her husband directly and asks if he has ever killed someone. Joo-ran is shocked when Jae-ho starts calling the spare phone to have a chat with Sang-eun.
Sang-eun puts his call on speakerphone and Jae-ho asks to meet Sang-eun to discuss the matter. She tells him that she’s busy that evening. After ending the call, Sang-eun tells Joo-ran that she will be going to meet Soo-min. Joo-ran offers to go with Sang-eun and promises to pay as much as she needs in order to get to the truth of the matter.
As she leaves Sang-eun’s house, Sang-eun asks Joo-ran if she trusted her husband. Joo-ran tells Sang-eun that she will protect her family at any cost, even if her husband was in the wrong. Later that day, Seung-jae goes to check out the apartment that he was planning on renting out. He also receives a text saying 50 million won has been transferred to his savings account.
At the same time, Sang-eun learns that she was fired from her job. Her ex-coworker tells her that the insurance company has sent people to the hotel for inquiry since there are a lot of policies under Yoon-beom’s name. Later that night, Sang-eun texts Jae-ho asking to see him the following evening.
Joo-ran apologises to Jae-ho for her behaviour from the night before. The next morning, Joo-ran sees Jae-ho off for work and rushes to Hae-soo’s house. Joo-ran borrows Hae-soo’s car and arrives at Sang-eun’s apartment complex to pick her up. Together, the two women head to Soo-min’s place.
Sang-eun goes into the house by herself and pretends to be Soo-min’s school teacher. From her father, Sang-eun learns that Soo-min was a high-schooler who had run away three months ago. He complains that Soo-min no longer answers his calls. Her father starts doubting Sang-eun and tries to advance towards her in order to assault her.
Sang-eun gets PTS (Post-Traumatic Stress) and recalls being assaulted by her now-late husband. She starts screaming and breaks a glass bottle so as to attack the man. Joo-ran makes it into the house in time and takes her away. Meanwhile, the detectives interrogate the watchman at Sang-eun’s apartment complex.
The old man tells the cops that Sang-eun was better off now that Yoon-beom was dead because of how she suffered at his hands. The detectives discuss how Sang-eun had the most to get out of killing her husband as they leave. Sang-eun and Joo-ran sit in silence after her breakdown while Joo-ran gets a text message from Jae-ho claiming that he will be late home from work.
On his way to see Sang-eun, Jae-ho gets a call from his father but the conversation is very sinister. Jae-ho is reminded of how he dragged Soo-min’s dead body into a closet. Sang-eun meets Jae-ho at a cafe to negotiate the blackmail amount. Joo-ran listens to the conversation from her car via Sang-eun’s phone.
Jae-ho tells Sang-eun that the ransom amount he dealt with Yoon-beom was 200 million won but Sang-eun provides a photocopy of Yoon-beom’s notes to show how he had asked for 500 million won. Sang-eun shows Jae-ho the photograph of him threatening Soo-min.
Jae-ho nonchalantly asks how Sang-eun moved Yoon-beom’s body from the driver’s seat to the passenger’s seat which stumps Sang-eun. The two have an unhinged conversation as Jae-ho asks Sang-eun to not let her guilt show when the cops eventually question her. Jae-ho leaves her alone at the cafe without buying into her negotiation.
Later that night, Joo-ran drives Sang-eun back home and tells her that she was willing to pay her 300 million won instead of her husband to protect her family. Sang-eun answers a call on Soo-min’s phone where a man asks to meet her at a motel room. Sang-eun gets out the car as Joo-ran drives off.
Sang-eun tells her aunt that she’s being kicked out of her apartment. She asks what 300 million won could buy her but the aunt claims it isn’t worth a lot. That night, Joo-ran starts wondering about what Jae-ho said to Sang-eun. Meanwhile, Jae-ho is at a nightclub drunk. He recalls finding Soo-min’s dead body in his house and how he buried her in the backyard as the episode comes to an end.
The conversation between Jae-ho and his father seems very off. It seems as though Jae-ho’s father was the man who used Soo-min as a prostitute and left her for dead at Jae-ho’s house. It is possible that Jae-ho hid Soo-min in the closet for a while before burying her in the yard late the night.
It also explains why Jae-ho was drugging Joo-ran and Seung-jae at night since it was the best time for him to sort his messes. Jae-ho looks like someone who has an awful lot to hide with the way he reacted to the news of one of his nurses getting married.
There are way too many secrets about him and the show is nowhere close to revealing them despite only four episodes left before its end.