Episode 9 of "When the Phone Rings" delves deep into a poignant reunion between I-na and Hee-joo, as the narrative revisits their conversation during I-na's visit to her stepsister. I-na is left astounded by Hee-joo's knowledge of Sa-eon's hidden truth, yet her heart is heavy with concern for Hee-joo, sensing that a shadowy adversary is orchestrating her downfall. Meanwhile, Hee-joo astounds I-na by speaking in her own voice, her bravery shining through as she recounts how she and Sa-eon chose each other freely. I-na, relieved to hear Hee-joo's voice once more, opens up about her fondness for being Hee-joo's elder sister. Together, they embark on a quest to uncover the identity of Sa-eon's mysterious antagonist.
Elsewhere, Sa-eon, driven by a heroic impulse, attempts to rescue Sang-hoon, but both men succumb to unconsciousness. Hee-joo, frantically dialing Sa-eon's number, soon realizes that alerting the authorities could invite a media frenzy and police scrutiny, compounding their woes. In a desperate bid for help, she turns to Sa-eon's parents, confiding in them that she can speak and revealing the truth about Sa-eon's non-biological ties to the family. Pleading with them to locate Sa-eon, she finds Kyu-jin agreeing to assist, albeit motivated not by compassion but by self-interest.
As Hee-joo exits the house, she encounters Mr. Min, who unravels another piece of the puzzle by disclosing that Sa-eon underwent eye surgery as a child to address his heterochromia. With this revelation, Hee-joo connects the dots and pieces together the intricate narrative.
In her car, Hee-joo receives an urgent call from Sang-woo, informing her that Sa-eon lies in a hospital bed, undergoing surgery. Without delay, she speeds to the hospital, her heart pounding. While awaiting news, she offers Sang-woo an apology for keeping him in ignorance for too long. It transpires that Sang-woo had visited Sang-hoon earlier in the day but was met with silence. Returning, engaged in a phone conversation with You-ri, he spotted Sa-eon making his way to Sang-hoon's residence and, driven by instinct, followed him, ultimately saving both men.
After undergoing surgery, Sa-eon is gently escorted to his room, where Hee-joo remains steadfast at his bedside, her presence a comforting constants until the first signs of consciousness flicker in his eyes. It is then that the realization dawns upon Sang-woo like the breaking dawn, illuminating the hidden romance between Hee-joo and Sa-eon. While Sa-eon lies in a slumber, Hee-joo whispers vows of protection, her resolve as steadfast as the morning star.
In his semi-conscious state, Sa-eon's mind drifts back to a pivotal moment – witnessing Sang-hoon receiving a bulky black bag from Paik Jang-ho. That fateful night, Sang-hoon's instruction to stay indoors was overshadowed by the harrowing sounds of Jang-ho committing a grim deed, mistaking the real Sa-eon for his unfortunate target. Awakened by the chaos, Sa-eon's fate took an unexpected turn as Jang-ho, recognizing an opportunity, chose to elevate him to the status of his grandson.
Elsewhere, You-ri's frustration boils over as Sang-woo abruptly ends their call without a single apology. Seeking solace, she crosses paths with Hyeok-jin and plants a seed of intrigue by sharing a critical tip about the ongoing case. Captivated by the revelation of the twins' existence, Hyeok-jin delves deeper into the enigmatic saga. Meanwhile, the kidnapper receives a chilling message from his cohort, a stark warning against straying from the path of duty. Flustered yet undeterred, he continues his preparations for Ui-hyong's upcoming TV interview, a spectacle akin to a reality show's grand finale.
Upon awakening, Sa-eon finds solace in Hee-joo's reassuring embrace, her words a balm for his wounds. Sang-woo's unexpected visit adds another layer of comfort; he reveals his role as a guardian of secrets, urging Sa-eon to focus on recovery without the burden of worry. Fortunate indeed, they are harbored within the confines of Sang-woo's father's hospital, a sanctuary where information flows as per his discretion.
Sang-woo's curiosity peaks as he questions Sa-eon's secrecy surrounding Hee-joo, accusing him of unfairness. Sa-eon, however, elucidates his reasoning – a shield of protection crafted from fear that the truth of his identity would turn allies into adversaries. Despite their disagreements, Sa-eon extends gratitude to Sang-woo for his timely intervention. Later, as he scrolls through his phone, Sa-eon is touched by the multitude of messages and voicemails left by Hee-joo, each one a testament to her desperate search and unwavering concern.
Later, Sang-woo leaves and meets with You-ri and promises to tell her more about his injuries at the right time. You-ri is worried about Sang-woo after seeing his injuries. She is also concerned that someone powerful is trying to kill the story. She asks Sang-woo to consider dropping the case.
At Ui-hyong’s house, the shooting preparation carries on without a hitch. Ui-hyong and Kyu-jin are displeased that Sa-eon is a no-show but still try to put a loving family facade. In the middle of the shoot, I-na shows up to play the role of Sa-eon’s wife at Ui-hyong’s request. Instead of calming the journalists’ curiosity by playing her sweet role, I-na asks prodding questions about Sa-eon’s childhood.
Things escalate when Ui-hyong gets a package thinking it is the abalone he ordered, but it turns out to be another threat from the kidnapper. Kyu-jin takes off to follow the man who delivered the package. She follows the kidnapper to the old family house. Meanwhile, the shoot is also called off. I-na refuses to sign the consent form to have her image shown or used in the programme. Ui-hyong is surprised since he thought I-na was his ally.
Back to Sa-eon, he panics when he comes back from talking to Sang-woo and finds Hee-joo gone. He calls her multiple times, but she refuses to pick up. It turns out she is at home, looking for the black phone so she can take it to the police. She assumes this is the only way she can protect her husband. She knows that the real Sa-eon is trying to hurt her husband and doesn’t want him to go scot-free.
Thankfully, Sa-eon finds her before she blunders and stops her. He confesses that he was able to forgive her because he could only endure all his suffering thanks to her. Without Hee-joo, he wouldn’t have made it. They return to the hospital, and Sa-eon admits that he tracks Hee-joo through her phone. She asks to do the same, but he begs her not to chase after him if he goes missing. Instead, he promises that he will always find his way back to her.
As they took a brief respite, Sang-woo dialed Sa-eon's number, conveying the urgent news that Sang-hoon had regained consciousness. Sang-hoon then unveiled the reasoning behind his name change, his motives for rescuing the genuine Sa-eon, and the grim location where he had interred all the individuals harmed by the impostor. Unbeknownst to Sa-eon, who had been relentlessly searching for Sang-hoon all these years, his former mentor had adopted a new identity. Furthermore, it was revealed that Sang-hoon had nurtured Sa-eon in his childhood until Jang-ho intervened and took him away.
The subsequent day, Young-woo conceived a whimsical notion—to visit Sa-eon in the hospital, accompanied by their colleagues, after hearing about their boss's misfortune. Sa-eon, despite his injuries, was adamant about fulfilling his professional commitments and delivering a pivotal speech at the hospital. Persuaded by Young-woo's enthusiasm, the rest of the staff agreed to tag along, intending to pleasantly surprise Sa-eon. However, Sa-eon was flustered by their unexpected visit and frantically attempted to keep them at bay, lest they glimpse Hee-joo, who was secretly with him. Young-woo felt slighted when Sa-eon requested a private audience with Do-jae alone.
Elsewhere, Hee-joo sought out Sang-woo to express her heartfelt apologies and gratitude. She confessed that she had known about his awareness of her speech capabilities, revealed by a nun at the orphanage who once witnessed Hee-joo serenading a child with a lullaby. Sang-woo reassured her, highlighting that Sa-eon was shielding her, a sentiment that echoed back to their attendance at the Ambassador's dinner during the show's premiere. Sa-eon had once declared Hee-joo as his Achilles' heel, safeguarding her identity to shield her from harm.
After a series of meticulous preparations, Hee-joo stood proudly beside Sa-eon on national television, interpreting for him in sign language. This triumphant moment filled her father and former colleagues with immense pride. Following the broadcast, Sa-eon entrusted Do-jae with the task of escorting Hee-joo home while he drove to the secluded site where Sang-hoon had concealed the victims' remains. Armed with the intention to gather incriminating evidence, Sa-eon aimed to unveil the truth at the opportune moment. Upon beholding the tiny graves, a poignant wave of nostalgia washed over him, reminding him of the eerie days when he witnessed Sang-hoon carting dark sacks.
He receives a phone call from Hyeok-jin, who has been diligently investigating the matter of the twins. After persistence, Hyeok-jin has finally gained entry to the DNA database of the missing person's family. He promptly forwards Sa-eon a snapshot of the document, revealing a shocking truth: Do-jae is the other twin! Sa-eon hastily dials Do-jae's number, but his calls fall on deaf ears.
In the meantime, within the confines of Do-jae's car, Hee-joo lies unconscious in the back seat, a victim of the tampered water. Desperate, Sa-eon attempts to reach Hee-joo as well, but she too remains unresponsive. A sense of chaos begins to envelop him, as if his entire universe is spiraling out of his grasp.
