In a chilling twist, a psychopathic executioner targets a young woman with hearing impairment, Kyeong-mi, after mistakenly stalking her mother. Kyeong-mi, who lives with her mother, works at a call center and one day leaves an unpleasant dinner with a customer to head home. However, her evening takes a deadly turn when the killer, Do-sik, spots her mother waiting for her daughter and changes his target to Kyeong-mi after another young woman, So-jung, walks by, oblivious to the danger.