Episode 8 of "The Potato Lab" unfolds with Mi-kyung carrying her colossal new teddy bear up the stairs, her spirits visibly high. She waves at Baek-ho as he exits, only to realize upon turning around that she's not entirely alone. Hwan-kyung and Ong-ju are lurking in the shadows, their curiosity piqued by her cheerful demeanor. Peering out the window, they spot Baek-ho, mistaking her joyful anticipation for salacious staking out. Her phone call to Baek-ho to clarify only fuels their amusement further when he teases her with promises of her soon witnessing "it" – a cryptic reference to his physique – sending her into a whirlwind of embarrassment.
Elsewhere, Hee-jin ventures out with friends, her mood taking a dive upon witnessing a couple's proposal on the beach. The scene triggers poignant flashbacks to her impulsive decision to propose to Ki-se, unaware of the half-hearted reservation in his heart. Though these recollections are sparse initially, they hint at Ki-se's lingering attachment to Mi-kyung, which intensifies upon learning of her relationship with Baek-ho.
The following day, Mi-kyung irritates Ong-ju by canceling their plans to spend time with Baek-ho instead. Her discontent is palpable as she sits pouting in the car alongside Hwan-kyung, who attempts to soothe her with a tender kiss – or, rather, a half-hearted attempt interrupted by the sight of Ki-se speeding down the road.
Ong-ju, driven by an intense emotion, abruptly leaves Hwan-kyung stranded by the roadside and rushes back to the guesthouse. There, she confronts Ki-se, berating him for leeching off his wife's affluent family and threatening him with bodily harm. Ki-se retaliates by accusing her of playing a part in his and Mi-kyung's breakup, escalating the tense confrontation.
Amidst the chaos, Baek-ho and Mi-kyung venture outdoors, and the intricate web of relationships among them starts to unravel, albeit partially. Though they are not privy to the full picture, Hwan-kyung elucidates the fragile dynamics at play, emphasizing the present precariousness. He and Ong-ju are united in their belief that Mi-kyung must confess all about her past escapades, but she dismisses their pleas and withdraws into her room, leaving them behind.
Elsewhere, Baek-ho confides in Ki-se, explaining his omission about Hee-jin's presence out of loyalty to his friend. When the conversation shifts to his romance with Mi-kyung, Ki-se cautions that this scandal will dog Baek-ho's career. Baek-ho, nonchalant as ever, brushes it off, urging Ki-se to find a hobby and refrain from nosing into others' affairs.
That fateful night, an urgent announcement reverberates through the ears of every Youngeul-ri resident: Myung-su, a beloved cow, has absconded from her home. Unaware of it being a common occurrence, Baek-ho hastily packs an abundant supply of emergency essentials into a cumbersome backpack. Together, Baek-ho and Mi-kyung, aided by Baek-ho's blindingly bright flashlight, eventually locate the calf after an arduous search.
The duo successfully returns Myung-su to her owner, a sweet, elderly lady suffering from Stage 2 dementia. Baek-ho thoughtfully attaches a location tracker to the cow, ensuring that if Myung-su wanders off again, her owner can swiftly trace her. This cow holds a special place in the lady's heart, akin to a son.
Upon returning home, Mi-kyung encounters a scene that shocks her to her core: Hwan-kyung and Ong-ju, both nude, entangled in a compromising position. Devastated by the betrayal of her best friend sleeping with her brother, Mi-kyung feels an overwhelming sense of disgust and disillusionment. Unable to bear the sight, she decides that her tenure in this house has come to an end and flees in a hurry.
Mi-kyung makes her way to the potato lab, where Baek-ho swiftly catches up with her. As they settle down to converse, Mi-kyung reveals that she views them both as family members, likening their gathering to that of two siblings. She attributes their romantic entanglement to mere boredom and loneliness, rather than genuine affection, and vents her thoughts passionately to Hwan-kyung. Despite her reluctance to return home, Baek-ho decides to seize the moment and accompanies her to a hotel.
The irony is not lost on Mi-kyung, especially as she is about to engage in a similar act with her boss, albeit her former boss. However, his intentions are not to share the room with her but rather to provide her with it. His sole purpose in bringing her there was to escape the sweltering heat of the lab, confident that the allure of their potential proximity would suffice to coax her away. Fortunately, she spares herself the comparison to a calf in heat. Baek-ho clarifies that he does not wish to exploit Mi-kyung's vulnerability, leaving the room entirely to her disposal.
At the workplace, Park Seung-hoon arrives at the lab to meet the potato gang. He promptly begins issuing orders, particularly to the Chief Section Officer, who is visibly irked when Mr. Park commands him to fetch coffee. It remains uncertain how long Park intends to stay at the lab, but his presence is far from welcome. Suspicions arise over his true motivations (obviously, to meddle and spy on Baek-ho).
Elsewhere, Hee-jin calls Ki-se and admits that she has been thinking of him. Their anniversary looms the next day, and Ki-se urges her to come to the office. Upon her arrival, Ki-se treats her with a chill that Hee-jin finds unsettling. She yearns for his embrace, but just as they share a hug, Baek-ho and Mi-kyung exit the elevator at Wonhan HQ. Mi-kyung realizes Hee-jin's identity and her connection to Ki-se, leading to an excruciatingly awkward encounter.
