Sohee, Kim Si-eun, a high school student who loves dancing in her spare time, is called in by one of her teachers who informs her that he has finally managed to secure an externship at a company called Human and Net, one of the many call centers for S-Plus Korea Telecom (a fictional telecommunications company). Before starting her externship, Sohee attends a training session that turns out to be makeup lessons as well as body shaming of the trainees. Once starting her externship, Sohee quickly learns that the primary aim of the company is not to help customers who want to cancel their services or troubleshoot issues, but to boost and sustain sales of S-Plus’s subscription services. The guidance she receives is to stall customers as much as possible so they eventually change their minds and stay with the services or buy additional offerings.
Throughout the externship, Sohee endures verbal abuse from rude customers who yell and swear at her, including an incident where a customer insinuates sexual assault, which pushes her to lash back in anger. She also notices how the company exploits its temporary workers by underpaying them, using the extern status as a justification. Team meetings become regular reminders that she must be among the top performers, otherwise she’ll face consequences. The atmosphere is tense, competitive, and merciless, with targets always looming over the trainees.
Junho, Sohee’s manager, stands out as the one person who seems to understand and support the workers as much as he can. Then one day, while walking to work, Sohee discovers Junho’s body in his car outside the company’s parking lot. The scene implies suicide by self-inflicted carbon monoxide poisoning. It later emerges that Junho felt guilty about the exploitation of externs and had sent whistleblower complaint letters to upper management, only to have them ignored.
A new female manager takes over and she is intensely focused on upping sales. She pressures Sohee to sign a form that rebukes Junho’s claims, a move Sohee signs reluctantly. At a company dinner, Sohee fights with another extern who resents her for doing so well and, as a result, raises the bar for everyone. After again receiving only partial pay despite meeting sales targets, Sohee shifts her attention to processing customer requests to cancel subscriptions rather than pressuring people to buy more. The new manager witnesses this shift and reprimands Sohee, who then speaks out about the blatant exploitation of externs and the underpayments. The manager mocks her for being poor and always chasing money, and in a moment of anger Sohee strikes the manager, landing her on three days of unpaid disciplinary leave.
While on leave and grappling with the guilt of signing the questionable claims about Junho, Sohee drinks with a friend, and in a moment of despair, she slits her wrists and is hospitalized. She asks to quit the externship, but her teacher rebukes her and urges her to return to work. Overwhelmed by the possibility of returning to the call center and still recovering from the night, Sohee, now slightly intoxicated, chooses to end her life by jumping into a reservoir.
The second half of the film follows the investigations led by detective Yoojin into Sohee’s suicide, along with a renewed inquiry into Junho’s death, which uncovers further details about Human and Net’s labor violations and the school’s role in placing externs to meet employment quotas. Across the examinations, the institutions often blame Sohee for her own death, characterizing her as undisciplined and hot-tempered. Yoojin attempts to pursue legal action against the companies and the school, but faces pressure from her superiors to drop the case, leaving the truth muddied and unresolved. The film closes with Yoojin watching an old video recording of Sohee practicing a dance routine—the only video left on Sohee’s phone before she turned it off and died—leaving viewers to wonder whether any real changes to safety practices or working conditions ever come about after Sohee’s death.
