Liu Pingguo, portrayed by Fan Bingbing, and her husband, An Kun, played by Tong Dawei, are a young migrant couple that has journeyed from northeastern China to Beijing in hopes of a brighter future. They find themselves residing in a run-down apartment, barely making ends meet through their low-wage jobs. An Kun earns a living as a window washer, while Pingguo toils as a foot masseuse at the Golden Basin Massage Parlor. The establishment is run by Lin Dong, a well-off businessman and shameless womanizer, known for his complicated relationships, played by Tony Leung Ka-fai. Lin's wife, Wang Mei, portrayed by Elaine Jin, practices traditional Chinese medicine but struggles with infertility.
The situation intensifies when Pingguo’s best friend, Xiao Mei, played by Zeng Meihuizi, finds herself fired after assaulting a customer. Seeking solace, Pingguo takes her friend out for drinks, resulting in her passing out at the parlor. This vulnerability catches Lin's eye—what starts as a flirtation escalates into a violent assault, witnessed by An Kun, who is outside washing windows. Enraged, An Kun engages in a campaign against Lin Dong, vandalizing his luxurious Mercedes-Benz and devising plans to blackmail him for ¥20,000. Meanwhile, Lin Dong neglects Wang Mei, prompting An Kun to confront her, leading to an unexpected seduction.
As events unfold, it becomes apparent that Pingguo is expecting a child. The uncertainty over the baby's paternity raises tensions: An Kun and Lin Dong, both unsure of their claims, devise a scheme—An Kun gets ¥20,000 initially, and if the child shares Lin Dong's blood type, he will take the baby, while An Kun stands to gain ¥100,000. However, should the baby be An Kun's, the couple will keep the child without any financial exchange. Amid this chaos, Pingguo remains silent, battling her own decision regarding an abortion, which she ultimately chooses to forgo.
As the pregnancy progresses, Lin Dong grows increasingly excited at the prospect of fatherhood. When the baby is born, An Kun discovers it is indeed his child. However, motivated by greed, he convinces Lin Dong otherwise, pocketing ¥120,000. Yet, witnessing Lin Dong's joy with the baby ignites a spark of jealousy in An Kun, leading to the kidnapping of the child, resulting in his arrest. After a release, presumably facilitated by Wang Mei—who chooses to leave Lin—An Kun attempts to reclaim his child, but Lin Dong categorically refuses.
In the end, Pingguo has moved in with Lin Dong, post-birth, with the help of a nursemaid. Eventually, she gathers the money An Kun tried to return, deciding to leave and start anew with her child. The film closes with both men in pursuit of her, making their way down a congested Beijing highway, only to face a breakdown that symbolizes the fractured lives left in the aftermath of their tumultuous choices.
