On the 17th floor of the Sky Tower, the third stall of the women's restroom hides "Filth" - a terrifying entity that combines workplace resentment and aborted fetuses. Designer assistant Su Qing develops a strange low-grade fever and phantom pain in her lower abdomen. Can cleaning Aunt Chen's salt and Buddha statues suppress the pollution? When the printer spits out bloody paper and pitch black hands ooze from the compartment, they must use baby dolls and blessing letters to perform the fatal purification of bending 30° at 3:17 in the morning...
