How could a large group of people across the country die within minutes of each other? What did the spiral on their hand even mean? Was this the work of a serial killer? Or was something more wicked at play in the streets of Korea?
Enter Captain Park Chanyeol an army soldier who is well-experienced in the realm of the supernatural having solved many of Seoul's unusual cases, though he prefers if no-one knew about his work as it only complicates matters.
Cue Byun Baekhyun a young college student who finds himself caught up in one of the biggest mysteries of the century.