Yeo-jin and Jae-yeong are two teenage girls who are trying to earn money for a trip to Europe. To reach this end, Jae-yeong is prostituting herself while Yeo-jin acts as her pimp, setting her up with the clients and staying on guard for the police. Things take a turn for the worse when Yeo-jin gets distracted from her duty and the police raid the motel where Jae-yeong is meeting with a client. To avoid getting caught, Jae-yeong jumps out of a window, fatally injuring herself.

A staircase leading to the dormitory of a remote boarding school usually has 28 stairs, but every so often there appears to be 29. When someone steps on the mysterious extra stair, the horror begins.

Yoon-Jung accidentally calls a stranger, instead of her boyfriend, and has phone sex with the unknown man. When Yoon-Jung's relationship with her boyfriend turns sour, Yoon-Jung meets Hyun-Seung, the stranger she had phone sex with.