In the dimly lit, empty garage, Baek Jin-na, enveloped in a sea of black attire, awaits silently. Meanwhile, within the pulsating confines of a nightclub, Park Woo-jin and a captivating young woman engage in a playful exchange of glances, while Cha Jin-wook and Min Yoo-hee sit in the periphery, observing with quiet introspection. Cha Jin-wook finds himself puzzled by Min Yoo-hee's serene demeanor, unaware that she has grown accustomed to Park Woo-jin's recurrent infidelities. From fiery outbursts to a stoic acceptance, her emotions have evolved, and now, her focus has shifted to Cha Jin-wook.
Elsewhere, Kim Hye-in and her impeccably dressed friend arrive at the nightclub, eager to confront Lee Si-rang. They attempt to queue early, only to be repeatedly thwarted by the bouncer. Kim Hye-in, undeterred, flashes her black card—a symbol of her affiliation with the prestigious Diamond Six—and the bouncer immediately grants them entry. As they scan the club for Lee Si-rang, they catch a glimpse of Cha Jin-wook and Min Yoo-hee together, but their mission drives them to continue their search. Ultimately, unsuccessful in their quest, they retreat to the bar for solace. Park Woo-jin, smoking outside, catches sight of Cha Jin-wook and Min Yoo-hee exiting together, a frown creasing his brow.
At the bar, Kim Hye-in and her friend nurse their sorrows, their hearts heavy with the image of Cha Jin-wook and Min Yoo-hee's proximity. The prospect of their fiancé being entangled with their adversary is an unsettling reality. Their conversation is interrupted by the sudden appearance of Lee Si-rang, whom they eagerly approach. He, clutching something intended for another, is taken aback to find Kim Hye-in as his intended recipient. Just as she interrogates him, a shadowy figure clad in a hat and black mask snatches the package containing Oh Si-eun's mobile phone and makes a swift exit. The chase ensues, with everyone in pursuit of the elusive figure.
In a twist of fate, Baek Jin-na, who had just obtained a crucial paternity test in the garage, is jostled to the ground by three individuals hot on the heels of the masked thief. Shielding the documents from prying eyes, she hastily rises and flees the scene. The pursuit continues, yet the package remains elusive. Later, at a convenience store, Kim Hye-in's wounds from the chase are tended to by her companions.
Lee Si-rang unravels the mystery behind Oh Si-eun's phone, explaining that his brother, acting out of kindness for Kim Hye-in, had requested Oh Si-eun to delete an incriminating video from her device. Amidst a rooftop altercation captured by Oh Si-eun's phone, his brother entrusted the phone to Lee Si-rang for safekeeping before departing the country. Encased in a password, the identity of the perpetrator remains shrouded in mystery. Now, with the phone stolen, the labyrinthine plot thickens further.
At this juncture, the mask of the enigmatic man in black is stripped away. Wu Shi-eun's phone, now unlocked, exposes Park Woo-jin as the one who shoved Wu down the stairs. Determined to uncover the murderer, Kim Hye-in and her companions procure surveillance footage from hotel security, meticulously combing through it for any lead on the shadowy figure. Unbeknownst to him, Park Woo-jin, in his bid to erase evidence, unlocks Wu's phone and stumbles upon incriminating videos of Kim Hye-in, an unforeseen twist that complicates matters further.
Baek Jina's secret and prolonged battle with substance abuse is laid bare, shaking the very foundations of Hanming Group's standing. Park Woo-jin, in a desperate attempt to win back Min Yool-hee's affection and start anew, flashes the compromising video of Kim Hye-in, thinking it might turn the tables. To Min Yool-hee's delight, this evidence not only implicates Baek Jina but also Kim Hye-in. She confronts Kim Hae-in, wielding a video of Hae-in and Park Woo-jin in an intimate embrace, coercing her into planting controlled substances in Baek Jina's locker. Kim Hae-in resists, but the pressure is overwhelming; her dream high school seems meaningless amidst the manipulations of the affluent, and her future hinges on compliance.
A crowd gathers around Baek Jina's locker, amidst whispers and accusations. A witness claims to have seen Baek Jina herself stash the drugs. Indeed, the substances are found. Simultaneously, Jin Huiren notices a wound on Park Woo-jin's wrist, a telltale sign linking him to the night's chase when Li Silang clashed with the man in black, who bore a similar injury. The chairman steps in, ordering Baek Jina to undergo a test, to which she objects, assuming her father's disapproval. To her shock, he has given his consent, rendering further protest futile.
Min Luxi stands firm in her belief that Baek Jina consumed drugs in the classroom, leading to a heated exchange with Jin Huiren. Just then, Baek Jina's test results arrive, and they are positive, confirming the worst.
