Episode 8 of "When the Phone Rings" kicks off with Sa-eon meticulously unpacking belongings, his fingers inadvertently stumbling upon an aged photograph that captures his youthful essence with Hee-joo. This tender relic brings us back to the poignant moment where Sa-eon, with a heart full of forgiveness, declared his undying love for Hee-joo, culminating in a kiss so powerful it seemed to shake the foundations of their world.
The following morning, Sa-eon takes it upon himself to prepare a heartwarming breakfast for Hee-joo, setting the stage for a more candid conversation. They both acknowledge that they had buried their genuine feelings for far too long under a shroud of silence. Sa-eon confesses that her presence made his home a haven and admits to his past harshness, stemming from a fear of baring his soul to her. Hee-joo, too, opens up, revealing her sense of suffocation within the confines of their home and her longing for the everyday, unassuming moments shared by ordinary couples. Over her meal, she shares the final message from their shadowy stalker.
Post-breakfast, Hee-joo hands the enigmatic black phone to Sa-eon, her voice tinged with melancholy as she expresses sadness over the prospect of no more calls. He decides against handing it over to the authorities, believing it to be a catalyst for their bond's deepening. Teasing her about her fierce alter ego and referencing the lingerie photograph that once stirred controversy, they find themselves in an embrace, leaving Hee-joo questioning whether this newfound closeness is merely a dream.
Elsewhere, the kidnapper receives a message from his accomplice, inquiring about the phone's retrieval. He responds with frustration, explaining that the hospital's tight security thwarted his plans. Under the guise of a wreath delivery, he attempted to infiltrate the facility following Sa-eon's arrival, only managing to catch a fleeting scent of him in the elevator. Ironically, it was Sa-eon's pleasant aroma that irritated him. He vows to his partner in crime that he will strip Sa-eon of everything he holds dear.
The following day, Hee-joo is haunted by a nightmare where Sa-eon deserts her. Jolted awake, she hastily makes her way to his room to ensure his presence. Finding him peacefully slumbering, she gently brushes her fingers across his cheeks, a tender gesture that rouses him from his sleep. He pulls her onto the bed, sharing with her that he's taken a personal day. Hee-joo, inspired by their recent adventures where Sa-eon heroically rescued her, expresses her desire for them to embark on a normal Couple activities To her surprise, Sa-eon reveals that his feelings for her extend far beyond what she had imagined.
As they engage in heartfelt conversation, Sa-eon receives an urgent call from Young-woo, pleading for his immediate presence at the office. Upon arrival, he discovers that Young-woo has orchestrated a surprise intervention aimed at rejuvenating his spirits. Shortly thereafter, Do-jae enters with crucial news: he has pinpointed the kidnapper's whereabouts in Hajeong, Gyeonggi-do. When questioned about his familiarity with the area, Sa-eon abruptly leaves, instructing Do-jae to stay put and avoid alerting the authorities.
En route, Reporter Hyeok-jin calls to inquire about Sa-eon's whereabouts, his concern mounting when Sa-eon mentions he's heading towards a confrontation with the kidnapper.
In Sa-eon's absence, Yeon-hui visits Hee-joo with a warning about I-na's return, urging Hee-joo to be cautious. Before Hee-joo can digest the information, a message from the kidnapper disrupts her thoughts, querying her knowledge of the real Sa-eon and attaching a clip from the Korean reality show, Live Alone.
Elsewhere, Sang-woo revisits the orphanage, prompting the sister to revisit memories of his first love, Hee-joo. She inquisitively wonders about Hee-joo's wellbeing and whether You-ri holds the title of Sang-woo's current love interest. This nostalgic discourse prompts Sang-woo to send Hee-joo a text, checking in on her. Intrigued by the missing orphanage children's case, Hee-joo decides to visit the orphanage herself to seek his insights.
Across the town, Ui-yong and Kyu-jin have resolved to proceed with their television interview, yet Ui-hyong harbors concerns and whispers confidential instructions to his assistant. The next time he attends an event, the media swarms him, inquisitive about his statement's discrepancy with Sa-eon's. Ui-hyong contends that Sa-eon was merely shielding him from a political uproar. As the conversation unfolds, an individual arrives with wreaths, professing insight into Sa-eon's actions. Subsequently, II-hyeong sternly advises Ui-hyong to regain composure, prompting Ui-hyong to invoke I-na, claiming a debt owed.
In the Hajeong district of Gyeonggi-do, Sa-eon arrives at the ancient manor to find a video awaiting him – the same one that had haunted Hee-joo's dreams, sent by her captor. The kidnapper brands Sa-eon a murderer and vows retribution. Soon after, Sang-woo arrives to reveal the manor's whereabouts to Hee-joo, promising to return the next day for an exploration, as twilight has fallen too deep. Sang-woo's curiosity peaks as he wonders about Hee-joo and Sa-eon's intense interest in the case.
As they depart, Sa-eon catches sight of them, plunging into a jealous fury. He trails them and phones Hee-joo. It is here that Sang-woo drops a bombshell: he knows Hee-joo can speak. Sa-eon manages to intercept them, insisting Hee-joo accompany him. Sang-woo attempts to halt her, but Hee-joo willingly steps into Sa-eon's car. Before departing, Sa-eon warns Sang-woo, casting aspersions on his intentions. He suspects Sang-woo either knows the perpetrator or collaborates with them. Regardless, he cautions Sang-woo to steer clear of Hee-joo.
During the return journey, Sa-eon pulls the car over abruptly, eager to unravel the mystery of Hee-joo's presence at the house with Sang-woo. She presents him with the message and chilling video she had received from the kidnapper. Misinterpreting the situation, Sa-eon assumes Hee-joo chased the lead out of a fear stemming from his troubled past. Hee-joo clarifies, revealing that she had been to that house before, understanding the terror of harboring a secret. She confesses her fear and anxiety, worried that she might lose Sa-eon, the only person who has ever loved and accepted her unconditionally. She fears her undeserving nature might snatch away this blissful happiness, causing her recent nightmares. Sa-eon, enfolding her in a warm embrace, inquires how he can reassure her of his unwavering support. Hee-joo, seeking a deeper connection, asks Sa-eon to unveil his secret, though he trembles with the fear of potential rejection.
At II-hyeong’s residence, Yeon-hui eavesdrops on I-na’s conversation with her father. To her astonishment, she discovers that II-hyeong had been aware of Sa-eon’s true identity and had sent I-na the DNA test results, confirming Sa-eon’s non-Paik lineage, mere days before the wedding. This revelation piques I-na’s curiosity about the agreement II-hyeong had brokered with the Paiks.
Flashing back, we witness a pivotal moment where Paik Hyong strikes a deal with II-hyeong, binding his family to fulfill whatever demands II-hyeong poses. The real Paik Sa-eon, it seems, was entangled in the fatal accident that claimed II-hyeong’s son’s life and left I-na deaf. In a poignant moment, II-hyeong urges I-na to let go of the past and focus on the present danger—the kidnapper’s awareness of the wedding deception and Hee-joo’s marriage.
Elsewhere, Ui-hyong and Kyung-jin sit for an interview hosted by You-ri, portraying themselves as a devoted couple. Kyung-jin, her voice trembling, requests to address her son, who has been tormented by life-threatening threats. In her heartfelt message, she reminds Sa-eon of the promise she made to always shield him, echoing words she once whispered to her real son as she confined him to the basement, believing it was for his protection.
After her recovery, Hee-joo returns to her workplace, greeted warmly by her staff who eagerly welcome her back. In the elevator, she seizes an opportunity to subtly flirt with Sa-eon, touched by his rapid proficiency in sign language. She treats her former colleagues to lunch, and they all marvel at her radiant glow. Meanwhile, Sa-eon diligently continues with his duties, despite the media's relentless focus on his personal life. In a bold move, he presents the last video sent by the kidnapper to the media, promising an exclusive interview to the journalist who can decipher the kidnapper's motive and message from the footage.
This action frustrates Young-woo. Suddenly, the office receives a call from the enigmatic old man who had previously unveiled the kidnapper's true identity. The old man leaves a chilling message, warning Sa-eon that someone is still alive. Elsewhere, Sang-woo is seen driving, seemingly trailing another vehicle.
Upon his return to the office, Young-woo informs Sa-eon of the old man's message and reveals that he traced the call to a fishing shop. The name of the shop jogs Sa-eon's memory, transporting him back to his childhood. Through a vivid flashback, we learn that Sa-eon once lived with the old man and witnessed an attempt by Paik Hyong to drown the real Sa-eon. Following this incident, the Paiks adopted him. Meanwhile, the kidnapper returns to the fishing shop and viciously attacks the old man.
Sa-eon hastily departs to meet the old man, unaware that Hee-joo remains at the office. As she browses through the photos from the retreat uploaded on their official site, Hee-joo notices that Sa-eon has a tender gaze directed at her in every picture. This discovery deeply touches her heart. Upon arriving home, she sends a text to Sa-eon, inquiring if he will be late. Unexpectedly, I-na visits and reveals Sa-eon's secret – he is not a Paik. However, Hee-joo dismisses it, asserting that it doesn't matter as she had already realized the truth when Sa-eon spoke about relinquishing his name and title.
The episode concludes with Sa-eon arriving at the fishing shop, which is engulfed in flames. He bravery attempts to rescue the old man, but the inferno intensifies, overwhelming him until he finally collapses, unconscious, before he could complete his rescue mission.
