The third episode of "In Your Radiant Season" opens with a much younger version of Chan pleading with his mother not to leave him. But she doesn't stop, and Chan is left with his strict father. Over the years, Chan tries to nurture his love for art, but his father hates the sight of it. He destroys all his art stuff and forces Chan to go to the US to study science.
When Chan's father arrives in the US for a conference, he visits his son and is enraged to find a box of artwork in Chan's room. He destroys all of it and yells at Chan as he storms out. Chan has finally had enough and decides to end his life. He's about to jump out the window when Ha-ran's messages loudly ping on his laptop and distract him. He sees that she's won a competition with the pen he (her boyfriend) gifted her.
Over time, they continue chatting, and Ha-ran's lively personality helps Chan laugh for the first time in years. At present, Chan decides he wants to do the same for Ha-ran. He asks her if she will allow him to be friendly with her, but she refuses. In turn, he says that he will make her want to be his friend. Back home, Chan shifts the sprig he saved from the glass of water to a pot filled with soil.
In the morning, Ha-ran and her family get a shock from her youngest sister, Ha-dam. She tells them that she wants to get married to her boyfriend, You-gyum. He's a baseball player who will play for the Mets in the US while she will complete her medical studies in South Korea. Na-na agrees to think about it after she meets him.
At work, Chan brings coffee for everyone at the office and Ha-ran avoids him. She even goes to a different coffee shop instead of Mr Park's cafe, Shim. Meanwhile, Ha-young ends up without cash at a food stall and calls the office for help. Yeon Tae-suk picks up the phone and arrives to help her out. At that moment, Ha-young gets a message from a friend setting her up for a blind date with a man named Cha-min.
Na-na starts suspecting that her granddaughters are lying about Ha-ran dating someone. In order to convince her, Ha-young pretends Ha-ran has a date that evening and drags her outdoors. Unable to go to Shim, Ha-ran tries to pass the time at various locations in the neighborhood but keeps avoiding Chan. When they eventually cross paths on the street, he stops Ha-ran from getting knocked over by an oncoming bike.
She stumbles and he instinctively tries to guide her towards a hospital, but she makes it clear that she's frustrated about not being able to visit her usual spots and doesn't want to be close to anyone. Chan says he'll just stand quietly by her side and convinces her to get her wrist checked. While she's being treated for a sprain, Chan realizes that she must have avoided him all day. He agrees to move out of Mr. Park's cafe and the neighborhood, so she can be comfortable.
When she's back home, she gets a call from Mr. Park, who asks her why she hasn't visited the cafe for a few days. She blames it all on work. When she overhears Mr. Park and Chan talking, she realizes that Chan's presence is beneficial to the old man.
Meanwhile, Chan realizes that his plant is looking a bit wilted. Mr. Park explains that the transplant into the new environment can lead to a shock - a comparison to what Ha-ran could be going through. Chan is about to break the news about moving out when Mr. Park says his presence is like that of a son to him.
The scene shifts to Cha You-gyum, who runs out from his baseball practice to go see Ha-dam. He's on the phone with her when she hears him shout. She gets really worried and runs out to see him, but thankfully, he's okay and was just helping someone in trouble.
At the office, Ha-ran arrives to see all her teammates really comfortable with Chan. She wonders if he asked everyone to be friends with him, not just her. During a meeting with Na-na, Chan says he's going to visit the palace to take pictures of the architecture for their work. She orders Ha-ran to go with him. Elsewhere, Tae-suk overhears Ha-young gushing about her blind date with Cha-min. He goes to a hotel for a meeting, where he sees Cha-min giving flowers to another girl.
Chan and Ha-ran head out to visit the palace and observe the colors and patterns on the walls. Suddenly, Chan isn't able to find Ha-ran, who's left her things behind. He searches for her and finds her sitting, in tears, at a gazebo. She says she heard a woman who sounded just like her mother and teared up. A flashback shows that the whole family was driving in two cars when the car with Ha-ran's parents and Ha-dam got hit by a truck. Her parents died on the spot.
At present, Chan recalls his own experience of hearing Ha-ran call his name while he was unconscious in the hospital. He tells Ha-ran it's normal to hear the voice of a person you miss. She then apologizes to him for her behavior up until now. She explains that she put up walls because she's scared of feeling that loss again but now, she feels trapped behind them.
Back at the office, Tae-suk hears Ha-young talking to Cha-min about meeting him and tells her that Na-na wants to see her. Ha-young cancels her plan and goes to Na-na's office but is surprised to find it empty.
On their way back home, Chan admits that he wants to be friends with everyone but it was different with her. He opens up about his own experience with depression. A flashback shows Chan responding to Ha-ran's messages and how their daily chats changed his life and even motivated him to return to art. Now, he says, he wants to show her how to escape the long winter she's experiencing. Just as they are heading their different ways, Ha-ran says she wants to learn how to escape the winter and he's more than happy to help. Just for three months. They shake on it. In the last few seconds of the episode, a passing car's headlights trigger Chan's memories from the blast. This time, he hears a sound that he hadn't heard before.
