Thomas stumbles upon an old diary in an antique district. As he begins to read the haunting tale of love and loss, Thomas realizes the diary carries a terrifying curse. Written many years ago by Jeong Hoon, an aspiring author, anyone merely exposed to the diary becomes a cunning facilitator of the curse. Even Thomas's girlfriend becomes his enemy. With no one to trust, Thomas desperately pursues information about Jeong Hoon and the diary itself. He embarks on a treacherous journey and discovers increasingly disturbing details about Jeong Hoon through dark, mysterious encounters with devil worship and even his own past.