A man wakes up missing his memories. Directed by a mysterious voice from a device in his ear, he sets off on a hostage rescue mission rife with danger.

Communicating via a walkie-talkie that transcends time, a profiler from 2015 and a detective from 1989 join forces to tackle crimes and injustice.

When Hye-Jung was young, her life was difficult. She was good at fighting, but also studied well. Overcoming her tough situation, she is now a doctor.

While defending an unlikely soul, the afterlife Guardians investigate an elderly man who’s outstayed his time on Earth, and delve into their own past.

A firefighter dies and arrives in the afterlife, where Guardians take him through the seven trials and a perilous journey through different hells.

On the day the 15-year statute of limitations expired on a high profile serial murder case that claimed the lives of 10 women, a family member of the victim throws himself off the building in front of Choi Hyeong-goo, the detective in charge of the case. Two years later, a man called Lee Doo-seok publishes a book titled "I am the Murderer" claiming responsibility for the murders that took place 17 years ago. His book becomes a bestseller because of the author’s charming looks and his vivid depiction of the crime. The detective and the self-proclaimed murderer meet face to face on a television debate show. Believing that Lee is nothing but a con artist, Detective Choi renews his search for the ultimate truth. Then another man appears suddenly, claiming he is the real killer.