The sixteenth episode of "Buried Hearts" unfolds with Dong-ju jolting awake from a harrowing nightmare, where Jang-seon's cold eyes reflected his own demise. As he emerges from slumber, a trembling hand reaches beneath his bed to retrieve a firearm. Illusions of Il-do haunt his consciousness, urging him to surrender the weapon now that victory is within his grasp, and to cherish the love he shares with Eun-nam.
Dong-ju ventures out to a serene restaurant, unaware of Gu-ho's clandestine observation from the confines of his vehicle. The air is thick with tension, as it has been a month since Jang-seon vanished without a trace.
The scene shifts to a pivotal meeting, where Dong-ju, Chairman Cha, and Choi Gi-hyeon converge. It transpires that Dong-ju has bested Guk-hui in their corporate rivalry, poised to be crowned the new CEO of Daesan Energy. With bold ambition, Dong-ju proposes a monumental merger between Daesan Energy and Daesan Chemical.
Elsewhere, Guk-hui and Ji Yeong-su exchange concerned glances, pondering Jang-seon's fate – whether he's met with foul play or defected to the opposing camp. Eun-nam's arrival stirs the waters further, revealing her recent appointment to the board of Daesan Energy. In a swift turn of events, Dong-ju is officially installed as the CEO, and he promptly unveils his vision to amalgamate Daesan Energy and Daesan Chemical into a formidable entity named Daesan E&C.
The tension mounts as Eun-nam confronts Dong-ju directly, her voice tinged with complexity as she inquires if he was behind Jang-seon's disappearance. Assuming the worst, she unexpectedly commends his supposed actions. Dong-ju then ascends to the chairman's office, where Seon-u, eyes burning with curiosity, demands to see the hidden vault. On the chairman's command, Dong-ju unlocks the mysteries within, revealing a mysterious package from a burger restaurant, tucked away in the vault's depths. The chairman's stern gaze falls upon Seon-u, promising the vault's password only when he proves himself worthy of leading the Daesan Group.
Back at their home, Eun-nam and Tae-yun perched themselves on a low wall overlooking a steep precipice, engaging in a nostalgic chat about the bygone days. As Eun-nam departed, Seon-u arrived unexpectedly and stealthily shoved...
Elsewhere, Won-bae and Dong-ju ventured into a law firm, seeking justice for Won-bae's frame-up by a hospital during his nursing days. To their surprise, the attorney handling their case was Hui-cheol. Amidst playful barbs and witty remarks, Dong-ju eventually exited the premises, but the air between them was unmistakably less tense than before. On the return journey, Won-bae inquisitively asked Dong-ju if he had anything to do with Jang-seon's mysterious disappearance, to which Dong-ju remained tight-lipped.
At work, Dong-ju and Eun-nam found themselves at Chairman Cha's office, but he was absent, having embarked on a leisurely drive. Informed by his secretary of the chairman's whereabouts, they followed him to a bakery once operated by Seon-u. When Chairman Cha eventually noticed Dong-ju and Eun-nam trailing him, he realized that his memory had once again deserted him.
A year leap forward in time, and Gu-ho's routine remained unchanged—watching Dong-ju frequent the burger joint. Subsequently, Dong-ju, Eun-nam, and Guk-hui convened to discuss business matters. Notably, Guk-hui now helmed Daesan Volt and seemed to have mended fences with Dong-ju.
Jang-seon's wife, Bo-yeon, dismissed Gu-ho with a severance package, instructing him to halt his fruitless search for Jang-seon. She then beckoned Dong-ju over for a meal, during which she opened up about Jang-seon's childhood, painting a vivid picture of his early years. Bo-yeon announced her plans to relocate and transform their house into a kindergarten. As a token of her fondness, she gifted Dong-ju a Photo of herself with a youthful Dong ju With a touch of warmth, Bo-yeon assured Dong-ju that his mother was a virtuous soul, one who refrained from taking the wrong path, even in dire financial straits, solely for Dong-ju's sake.
Dong-ju retrieves a package from the bustling burger joint and discreetly tucks it away inside the chairman's impenetrable inner vault. Upon his departure, a hidden window silently swings open behind a dusty shelf, revealing a hand sneaking the package away. This hand belongs to Jang-seon, who has been confined within a cramped storage room, shackled to the cold floor, for a harrowing stretch of over a year. He finds himself immersed in a sea of cash and glittering gold bars, a stark contrast to his desolate surroundings.
A vivid flashback unfolds: Dong-ju administers a potent sedative to Jang-seon before speeding off into the night. Jang-seon awakens to find himself ensconced in the minuscule, windowless chamber nestled behind the vault's formidable walls. Dong-ju, with a hint of cruelty in his voice, boasts about the luxury of having installed a tiny bathroom just for him.
In the present moment, Dong-ju saunters back to visit Jang-seon after indulging in his burger. Jang-seon, eyes filled with defiance, demands to know Dong-ju's ultimate desire. Dong-ju, unmasked in his greed, reveals his intentions: to claim Jang-seon's entire fortune. As Dong-ju turns to leave, Jang-seon, fueled by desperation, forcefully pushes open the window and hollers to Dong-ju, his voice echoing through the confined space, that his dying wish is to pass away in the comfort of his own home.
Dong-ju subsequently encounters the Elder and informs him categorically that no further funds from the National Patriotic Fund will grace his pockets, emphasizing that the resources will be reallocated more judiciously. Leveraging Jang-seon's meticulously compiled files, Dong-ju possesses concrete evidence of the Elder's misdeeds and issues a stern warning against any further threats directed towards him or Daesan. We then witness Jang-seon, having transferred his entire fortune to Dong-ju as promised, awakening from his slumber to find his shackles gone. The vault door stands ajar, prompting him to bolt out into freedom.
Meanwhile, the chairman's desk now bears the inscription 'President Seo Dong-ju,' marking a symbolic shift in power. Dong-ju, watching Jang-seon's departure with a heavy heart, finally takes his seat at the desk, but his emotions swiftly overtake him, causing his eyes to well up with tears. Jang-seon, upon returning home, is startled to find his residence transformed into a kindergarten, a stark reminder of life's unpredictable turns.
Elsewhere at Daesan, Tae-yun crosses paths with Dong-ju, revealing his six-month tenure at Daesan Volt hasn't ignited his passion. Dong-ju persuades him to persevere a little longer, suggesting that time might reveal his true calling. Just then, Tae-yun receives a call from Chairman Cha, summoning both of them.
Later, Dong-ju and Tae-yun join the Cha family for dinner, an evening made sweeter by Chairman Cha's momentarily clear mind, a rare reprieve from his dementia. However, the tranquil scene is abruptly interrupted by a heated exchange between Tae-yun and Deok-hui. Tae-yun, still grappling with the legacy of his parents' misdeeds, pleads with his mother for them to start anew, far from their troubled past. Deok-hui, however, harbors ambitions for him to eventually steer the helm of Daesan.
Thus, the intricate tapestry of their lives continues to unwind, each thread weaving a story of hope, struggle, and transformation.
In the chairman's office, Dong-ju engages in business discussions with the chairman, but the latter's memory lapses once more, leaving him seemingly anchored in the bygone era. Internally, Dong-ju ponders embarking on an extended sabbatical.
At Daesan, Dong-ju entrusts Eun-nam with the safe's code, acknowledging her proven leadership abilities and recent accomplishments. Sensing his impending departure, Eun-nam grasps the significance of this gesture. Dong-ju confesses that while he has extracted his revenge on Jang-seon, he now finds himself adrift, questioning the very essence of right and wrong. Seeking clarity, he decides to venture forth on a journey of self-discovery.
Later, Eun-nam chauffeurs Dong-ju to the coastline. As he strides away, she calls out to him, and he turns back, sharing one final kiss before disappearing towards the horizon of the vast ocean.
Meanwhile, at the Cha residence, Seon-u and Tae-yun sip coffee and indulge in a cordial chat, their camaraderie evident. Tae-yun discreetly sends Dong-ju a text suggesting that Seon-u might indeed be a more suitable candidate for Daesan's leadership. Unexpectedly, Seon-u returns, pushing Tae-yun off a wall and sending him tumbling down a steep cliff.
Elsewhere, Jang-seon finds himself back behind bars.
On a luxurious yacht, Dong-ju scatters Il-do's ashes upon the waters, a solemn ritual for the departed. He then retrieves his violin and an assortment of firearms – the one that Il-do used to shoot him and the one he confiscated from Jang-seon during a suicidal threat. The mid-credit scene of Buried Hearts Episode 16 reveals Ji Yeong-su and Seon-u posing for a portrait with Chairman Cha, while Guk-hui occupies her office at Daesan Volt and Deok-hui lies ailing in a hospital bed, overwhelmed with grief.
Eun-nam creates another painting, depicting a yacht gliding across the sea, but this time, it carries two figures instead of one. She fondly requests Dong-ju to return, if not permanently, then at least for a fleeting moment.
