Have you had a bitter experience because of a stranger you let in your house? Don’t be a good Samaritan inviting a stranger into your house recklessly. Chang-soo invites a stranger man to his house, whom he met through his photography hobby club. The two drinks together and fall asleep. When Chang-soo wakes up, he finds himself tied up and there stands his wife looking scared.

The story of an ordinary woman with dream walking ability to control other people's dreams against the backdrop of a noisy city in a serial murder case and a serial killer who can control other people's dreams.