Sae-oh, une jeune femme vivant recluse chez son père, doit affronter son agoraphobie après que leur maison a été anéantie par les flammes. Selon la police, son père aurait provoqué une fuite de gaz afin de se libérer du surendettement. Mais Sae-oh soupçonne un collecteur de dettes d’être à l’origine de l’incendie et prépare sa vengeance. En parallèle, Ki-jeong, une enseignante au bout du rouleau, apprend que sa demi-sœur s’est suicidée. Rongée par la culpabilité, elle tente de retracer ses derniers jours et découvre qu’elle était victime d’une vaste escroquerie. Au terme de ces deux enquêtes alimentées par la paranoïa et la haine, leurs lignes de vie se croiseront de manière inattendue, révélant les innombrables façons dont la pauvreté nous rapproche ou nous divise.

When Shin Ha-jeong, Shin Ki Jong's half sister with whom he had never been particularly close, is discovered dead after drowning in a river, Shin Ki-jeong steps up to solve the mystery surrounding her death. Ki-jeong, who has been pursuing the mystery with a sense of indebtedness rather than sorrow or longing, stumbles upon the phone number of a man on his half-sister's call log. Yun Se-o was the name of the man whom she so desperately wanted to meet in her final moments. Why was she so desperate to talk to him?

Meanwhile, Yun Se-o's father is believed to have committed suicide due to mounting debts. Yun blames himself, believing that his father would not have made such a lonely and painful choice had he not been absorbed in a multi-level marketing scheme. To kill Lee Su-ho, the loan shark who threatened his father, Yun begins to shadow his every move. One day, someone approaches Yun and asks if he remembers the name Shin Ha-jeong...

아버지 외에 누구와도 관계 맺지 않고 집 안에만 칩거하던 윤세오는 집이 불타버린 후 광장공포증과 마주하게 된다. 경찰은 아버지가 불어나는 빚을 감당하지 못해 가스 호스를 끊고 폭발 사고를 일으켰을 것이라 추정한다. 그러나 윤세오는 화재의 원인이 채권 추심자라고 생각하고 복수하리라 결심한다. 한편, 벼랑 끝에 몰린 교사 신기정은 이복동생이 자살했다는 연락을 받는다. 죄책감으로 죽음의 사연을 추적하던 신기정은 동생이 다단계사업의 희생자였다는 사실을 알게 된다. 가난이 사람을 이어주기도 하고 관계를 끊기도 하면서, 편집증과 증오로 가득 찬 두 주인공 삶의 선은 예상치 못한 방식으로 교차한다.