Episode 4 of "Unmasked" kicks off with So-ryong being mobbed by a flock of reporters, their microphones jabbing the air as they pepper her with inquiries about the semi-nude photograph circulated by Dr. Trigger. Just then, Han Do arrives, his newly styled hair glistening, and uses his umbrella as a shield to extricate her from the throng. With a stern rebuke, So-ryong silences the reporters before striding into her office, where she finds Cho Hae-won awaiting her.
Across town, in a separate KNS newsroom, Jin-woo finds himself in conversation with Ye-rim, his colleague and secret lover. Their liaison was the subject of the first video Dr. Trigger unveiled. Jin-woo confronts her, demanding to know if she was behind the posting of So-ryong's photograph, to which she vehemently denies.
Elsewhere, Team Trigger delves into the mysterious pattern: every journalist who crosses paths with Cho Hae-won ends up unemployed. Undeterred, So-ryong is resolute in her intention to interview her. Meanwhile, in a conference room, Han Do keeps Hae-won company. She feigns dropping her ring, using the opportunity to brush her hand against his thigh as she retrieves it. Boldly, she even snatches his phone to jot down her number.
Upon So-ryong's entrance, Hae-won springs into action, presenting her with an NDA contract to sign. The conversation then pivots to the events of two decades ago, when Cha Seong-wook vanished without a trace. His last known sighting was on February 11th, during the premiere of his maiden film. Hae-won had called him and subsequently headed to his apartment to meet him. Now, she confides in So-ryong a long-held secret: another woman, adorned with long burgundy nails and a formidable hat, had preceded her to Seong-wook's place.
When So-ryong inquires about the timing of this revelation, Hae-won admits that her love for Seong-wook was so profound back then that she would prefer people to suspect her rather than contemplate his infidelity.After her departure, Gi-ho steps in and fills in the remaining blanks, painting a vivid picture of Seong-wook's meteoric rise to fame within a single year, followed by an abrupt disappearance. Hae-won, not merely his sweetheart but also the offspring of Cho Tae-sung, the esteemed chairman of the mighty Hanju Group, adds another layer of complexity to the narrative.
Back at the office, an unexpected visitor arrives – the wife of a Trigger team member, a determined public defender. She enters So-ryong's domain with a heart-wrenching tale about her newest client, Lee Yu-mi, a young girl who, driven to desperation, stabbed her father and came perilously close to disfiguring him permanently. The lawyer reveals that the father had been raping her since the tender age of six, a heinous act that she tried to report to the police at 13, only to be thwarted by her father's formidable influence as a prosecutor. Flashbacks flicker like haunting echoes, depicting the father's brutal mistreatment of his mute wife, even brutally cutting out her tongue, for daring to defy him. Pleading with So-ryong for assistance, the lawyer lays bare the desperate plight of Yu-mi.
Moved by the lawyer's plea, So-ryong consents and ventures to the prison to meet Yu-mi. Drawing parallels from her own life, with the compromising photo taken by Jin-woo ever-present in her mind, she paints a poignant picture of betrayal by a loved one. Yu-mi, finally engaging with her gaze, declines the offer to participate in the show but warns So-ryong to steer clear of Jin-woo.
Elsewhere, President Koo receives intelligence suggesting that Dr. Trigger is embedded within KNS. Manager Son Hui-won, relentless in his pursuit, once again pressures Koo to terminate So-ryong's employment and bestow power upon Han Do. Returning to the Trigger office, Chief Park Dae-young makes an announcement that sends ripples through the ranks: Han Do and Gi-ho have been appointed producers of Teams Four and Five, respectively, setting the stage for an intense drama unfolding behind the scenes.Son Hui-won proceeds to conduct a series of interviews with the members of the Trigger team, delving deeper into the enigma of Dr. Trigger. He confronts Hong Na-hee about concealing her parenthood and probes another staff member about their sexual orientation. He even mocks Gi-ho by revealing that So-ryong had cast her vote for Han Do, not him.
When it comes to Han Do's turn, President Koo strides into the room, seizing control of the investigation. He tasks Han Do with collaborating with So-ryong on the Cha Seong-wook case and reporting directly to him. In exchange, Koo offers Han Do an uncapped company card, a gesture loaded with intent. Shortly thereafter, So-ryong enters, pleading with Koo to cease monopolizing her subordinate's time. Koo retaliates by hinting at So-ryong's partiality towards Han Do, suggesting she elevated him to producer status to scapegoat him later.
So-ryong then instructs Han Do to chauffeur her to the hospital. There, she encounters Yu-mi's mother, who is nursing her husband. She beseeches Yu-mi to lend a helping hand to her daughter, but Yu-mi curtly dismisses them. Han Do's rage ignites upon discovering the father's deplorable actions.
Back at KNS, internal auditors escort Jin-woo to President Koo and Hui-won, having uncovered incriminating photos and videos of Dr. Trigger on Jin-woo's possession. Jin-woo vehemently denies being Dr. Trigger and implores them for assistance.
Elsewhere, Park Dae-young reconvenes with his former superior and ex-Trigger chief, Seong-chun. He inquiries about the Cha Seong-wook case, and Seong-chun reveals they were on the brink of releasing an episode on it, but the night before, his colleague swooped in, seizing the tape and fleeing. This colleague, it transpires, is none other than President Koo.Han Do, still seething over Yu-mi's plight, storms back to the hospital to confront her mother. With venom in his words, he recounts how his own father brutally amputated the tip of his pinkie finger, emphasizing how childhood abuse carves an indelible scar into one's soul. Yu-mi's mother, using a notepad as her voice, solemnly conveys to him that should her husband perish, Yu-mi would be labelled a murderer—a fate she desperately strives to avert by keeping him alive.
Returning to KNS, Han Do finds himself face to face with Gi-ho, who confronts him about So-ryong's preference for Han Do over him. Gi-ho declares his desire for recognition and vows to challenge Han Do fairly and squarely.
Near the serene riverside, So-ryong finally meets Jin-woo, her demeanor anything but calm. She lambasts him for snapping the incriminating photo and proceeds to expose how each of his news articles, meant to shine a light on victims, has actually caused them further harm due to his unethical actions. She severs their relationship, and he, with astonishing audacity, dares to ask her to mislead the company into believing the photo was taken with her consent. When he inquiries about the ring, she retorts by hurling the ring box out of the car window and crushing it under her tire.
After repeated refusals, Yu-mi eventually consents to meet So-ryong. Steeling herself for the battle ahead, she unfolds her harrowing tale of becoming pregnant and giving birth only to witness her father murder the innocent child. It was then that the decision to eliminate him was solidified in her heart. Yu-mi's heart-wrenching narratives about her mother evoke tears in So-ryong's eyes, stirring memories of her own late mother.
A fleeting glimpse into the past reveals a young So-ryong rushing to the hospital, only to catch a harrowing sight of her mother—two bloody legs visible, hinting at a tragic demise long ago.
Yu-mi further reveals that it was Han Do who swayed her decision, by delivering a note penned by her mother, imploring her not to become a murderer, straight into her hands. Upon reading her mother's words, Yu-mi's resolve to fight for her survival wavered. Meanwhile, Jin-woo tendered his resignation, marking the end of his tenure. As So-ryong departs the prison amidst the downpour, her umbrella is swept away by the gusty winds. Han Do, arriving on the scene, promptly shields her with his own umbrella and breaks the heartbreaking news that Yu-mi's father has just passed away in the hospital. In response to this sorrowful tiding, So-ryong, oddly, finds solace in dancing and hollering in the rain.
Later, Yu-mi's mother visits her daughter in prison, and the two share an emotional reunion, their hearts beating in unison once again. Elsewhere, Han Do chauffeurs So-ryong, who now battles a cold, to procure medicine. As he steps out to make the purchase, a partially constructed building nearby starts to crumble onto the road, casting a shadow of danger over the tranquil moment. The mid-credit scene of Unmasked Episode 4 depicts a youthful So-ryong heading out for school, her mother's voice echoing in the background, gently reminding her to have breakfast before she leaves.
