The third episode of "Surely Tomorrow" opens with Kyeong-do and Ji-woo being grilled by airport police over the commotion they'd caused. Kyeong-do explains that he recognizes Ji-woo and only wanted to speak to her, producing a photo from their reunion as evidence. The police are satisfied and let them go. Outside, Kyeong-do tries to persuade Ji-woo to stay, but she refuses, asking him to foot the bill for her first-class tickets, which amount to a shocking 7.2 million won.
Flabbergasted by the price, Kyeong-do suggests she either return home or stay in a hotel. Ji-woo reveals that she's sold all her belongings and no longer has a home, implying she'd need to stay in a five-star hotel at his expense. Reluctantly, Kyeong-do agrees to let her stay at his house before heading to work.
Kyeong-do informs Ji-yeon of Ji-woo's whereabouts and asks her to pick up her sister. Ji-yeon refuses, saying it would only upset Ji-woo further, fueling Kyeong-do's suspicion that the Seo sisters might be playing some elaborate game with him.
Meanwhile, Ji-woo calls Se-young to tell her she's staying at Kyeong-do's place. Se-young and Woo-sik excitedly imagine a romantic reunion playing out between the two. Woo-sik later calls Kyeong-do to tease him about confessing his feelings, but Kyeong-do dismisses it with a wave of his hand.
That night, Kyeong-do returns home to find Ji-woo drunk and wearing the same orange T-shirt. She flirts playfully with him before collapsing into his arms. He gently pats her back to calm her down, puts her to bed, and sits beside her for a while.
A flashback takes us back to 2007, when Kyeong-do was working as a waiter at a luxury restaurant. He notices Ji-woo dining with her family and friends, overhearing a conversation about her return to the U.S. and struggles with weight gain. Ji-yeon takes Ji-woo outside for a brief chat with Kyeong-do, but their moment is interrupted when Ji-woo's mother, Hyun-kyung, spots them and asks the manager to change their waiter. The manager later informs Kyeong-do that Ji-woo is the heir to Jarim Apparel, leaving him stunned. Ji-woo considers texting Kyeong-do that night but decides against it.
The following day, she encounters him outside the university's gates, but her embarrassment prevents her from speaking. Kyeong-do reassures her that she has done nothing wrong and urges her to be honest with her feelings. In the present, Kyeong-do's mother, Nam-sook, pays a visit to his apartment and notices Ji-woo's heels by the door. She quietly departs without delivering the dry-cleaned clothes.
Later that morning, Ji-woo apologizes for her behavior from the previous night. Over coffee, she admits to acting strangely around him. Kyeong-do recalls Ji-yeon's words about Ji-woo's depression and her fear that Ji-woo might spiral out of control if she learns about her sister's Alzheimer's. He warns Ji-woo that drinking every day will ruin her life and implores her to stop.
Ji-woo insists that she cannot return home and face her mother again. As Kyeong-do leaves for work, Ji-woo decides to stay until she books new flight tickets.
Meanwhile, Min-woo meets with investor Bae Jun-soo, who presses him to convince Ji-yeon to sell Jarim Apparel quickly. Min-woo claims that Ji-yeon is already losing her memories and will struggle to maintain her lies.
Around the same time, Da-hye calls Min-woo from prison, but he ignores the collect call. Oh Gun, overhearing the conversation, later warns Ji-yeon about Jun-soo's intentions.
That evening, Kyeong-do returned home to find Ji-woo under the shower's tender embrace. Stepping out to procure provisions, the two sat down to a meal filled with the quiet understanding that had once been theirs. Ji-woo's subtle hints of unrequited feelings stirred within Kyeong-do, causing him to leave in haste, claiming the apartment was haunted. He spent the night in a public sauna, seeking solace in the warmth of strangers.
Meanwhile, Ji-woo lingered in the apartment, while Kyeong-do subsisted on convenience store fare and worked tirelessly. Han-kyung noticed his exhaustion at work, a testament to the strain he bore in silence. Ji-woo reminisced about how protective Kyeong-do used to be, the way he had once stood up for her when she revealed her heritage to the drama club.
A flashback took them back to a time when Se-young suggested a beach trip for a workshop, and the group bonded over photos, drinks, and late-night conversations. Ji-woo and Kyeong-do grew closer, taking a couple of photos and talking through the night. The next morning, Ji-woo built sandcastles alone before confessing that she had noticed Kyeong-do when he was searching for a 500-won coin and deliberately pursued him. They admitted their feelings for each other, and Kyeong-do later gifted her an orange dress from Jarim Apparel, placing the coin in a pocket watch as a symbol of their love.
In the present, Ji-woo visited Dongwoon Daily to announce her move out, ensuring Kyeong-do's colleagues overheard her words. After she left, they teased him about rekindling his romance. At home, Kyeong-do found empty beer cans and soju bottles, a reminder of his struggles with addiction. As he recycled them, he ran into Nam-sook, who warned him against slipping back into old habits.
The next day, Ji-woo confided in Se-young about her argument with Kyeong-do and mentioned that he had refused to drink with her. Se-young revealed that Kyeong-do had become addicted to alcohol after Ji-woo had left him the second time. Shocked, Ji-woo confronted Kyeong-do about his addiction and rehabilitation, calling him an idiot. But he calmly took responsibility for his drinking and urged her to stop before it got worse. They talked about how she had left without saying goodbye years ago, and Ji-woo apologized for teasing him, asking him to stop worrying about her.
At a convenience store, Ji-woo nearly bought alcohol but stopped herself and returned home to her family. There, Hyun-kyung pressured her to take over Jarim Apparel and accused her of running from responsibility. Ji-woo confronted her mother about having an affair, revealing that Ji-yeon was her half-sister. She accused Hyun-kyung of keeping her away from Ji-yeon's father and only pushing Ji-yeon forward now that his fortune was at stake. Hyun-kyung panicked when Ji-woo revealed Ji-yeon already knew the truth but showed no remorse for how she had treated Ji-woo, leaving her devastated.
That night, Se-young called Kyeong-do when Ji-woo's phone was unreachable. Fearing the worst, he called a locksmith. Inside Ji-woo's house, they found her unconscious on the floor. The episode ended with Kyeong-do rushing her to the hospital in a desperate bid to save her from the darkness that threatened to consume her once again.
