In the tranquil suburbs of Seoul, the opening scene of "The Trunk" Season 1 Episode 1 sets a somber tone. Noh In-ji (played by the ever-captivating Kim Hye-soo), a professional in the peculiar field of contract marriages, is seen attending to her latest spouse with a clinical detachment that speaks volumes about her character. Her efficiency in severing ties post the husband's demise is a testament to her reputation as the best in her company. Despite her boss's insistence on a break, In-ji, driven by an unseen force, declines, setting the stage for her newest and most enigmatic contract yet—with Han Jeong-won (the charismatic Lee Jung-jae).
Han Jeong-won, a wealthy and successful music composer, is the talk of the town, not for his melodies but for the rumors of drug addiction following his divorce. The truth, however, is far more tragic; his insomnia drives him to overdose on sleeping pills, a secret only his close friends are privy to. His aversion to the family chandelier, a relic of his marriage to Lee Seo-yeon (the elegant Kim Hee-ae), is a symbol of his unresolved past. In-ji's arrival at his home is met with a peculiar ease as she dons the wedding ring he has chosen for her, signaling the beginning of their contractual union.
Jeong-won's life takes a tumultuous turn when he is apprehended by the police, who suspect him of drug use based on an anonymous tip from a co-worker. His outburst at the co-worker and the calm intervention by his boss, Hyeon-cheol (the seasoned Yoo Hae-jin), highlight the complex dynamics at play. Hyeon-cheol's confusion over his role as boss is a subtle nod to the underlying power struggle within the music label, which Jeong-won actually owns.
The rumors of Jeong-won's drug addiction reach his ex-wife, Seo-yeon, through Hyeon-cheol's wife, Yun-a. Seo-yeon's cold demeanor during a dinner with Jeong-won is a stark contrast to his lingering affection. Their history as high school sweethearts is tainted by a life-threatening incident involving Seo-yeon, which led to their separation. Jeong-won's gift of earrings to Seo-yeon and her subsequent departure with her new, younger husband, leaves a bitter aftertaste.
Jeong-won's desperation is palpable as he follows them, only to find the earrings abandoned in the car. His repeated calls to Seo-yeon go unanswered as he watches her engage in an intimate moment with her husband. His frustration culminates in a violent act of breaking her car window, leading to his arrest. Yet, Seo-yeon's cover for him once again speaks to the twisted bond they share.
In-ji's arrival to take him home is a turning point. Jeong-won's attempt to maintain distance and his awkwardness with the protocol of their contract marriage are met with In-ji's pragmatic approach. Her suggestion to read the manual is a stark reminder of the transactional nature of their relationship.
The night brings a haunting nightmare for Jeong-won, where he witnesses his mother murdering his father. His plea for her to stop is a chilling revelation of his understanding and complicity. In-ji's continued efforts to care for him, despite his refusal to eat, highlight her commitment to her role.
Meanwhile, the police discover a rafter and an expensive trunk, similar to In-ji's, along with a Prada wallet, hinting at a darker subplot unfolding in the background. In-ji's return to her small apartment reveals a complex web of secrets. Her neighbor's advice to move on from her missing fiancé and In-ji's jest about having killed him add a layer of intrigue to her character.
The news of Eom Tae-song's discharge from a mental hospital sends a wave of worry through In-ji, who ensures she is prepared for any threat. Jeong-won's panic attack before meeting Seo-yeon to clear the air about the car incident is a testament to his emotional turmoil. Seo-yeon's cold wish for his death contrasts with her public facade of support.
The episode concludes with a dramatic turn as Jeong-won and In-ji's bickering leads to an accident involving the chandelier. In-ji's protective instinct is revealed as she shields Jeong-won from the falling glass, sacrificing her own safety. The police's interrogation of Jeong-won about the trunk's ownership ends on a cliffhanger, leaving viewers eager for the next installment.