Sohee is a high school student at a vocational school. She gets excited to land an externship at a major internet provider's call center, but the prized office job turns out to be a nightmarish workplace. She becomes under immense pressure from the company to reach the best team target. The work is daunting even to a gutsy girl like Sohee, but to make matters worse, externs only receive a fraction of the normal wages. She is gradually torn between anger, disappointment, and pressure. Eventually, it leads her to death.Detective Oh Yoo-jin becomes in charge of this case. She starts to follow Sohee's traces and the people around her to reveal the causes of her death. As she investigates Sohee's case, Yoo-jin comes to find out that the hidden side of the incident is more upsetting and demoralizing than she ever could have imagined.