In Korean folk traditions, "seire" is the twenty-one days after a baby is born in which they're uniquely vulnerable to bad luck, curses - even evil spirits. Many superstitions surround these first three weeks in a baby's life, and new mother Hae-mi carefully follows every one of them. Father Woo-jin is reluctantly willing to play along, but when he attends an ex-girlfriend's funeral, he unwittingly opens the door to to dark supernatural dangers. Plagued by terrible nightmares, the skeptical Woo-jin gradually begins to understand the seire custom, as he is forced to unravel the mystery of what is haunting him and his family in Kang Park's "chilling indie horror debut" (Screen Anarchy) heralding the arrival of a fresh new voice in Korean genre cinema.