Starring Park Hae-soo, Lee Hee-joon and Claudia Kim, the series tells the story of three leading characters who dig through secrets of the past 30 years to find a culprit named 'Chimera'.

Chimera is the name of a monster that has the head of a lion, the body of a goat, and the tail of a snake, and breathes fire through its mouth.

The filming of the series, produced at a cost of ₩13 billion, was temporarily halted in June 2019 due to sexual harassment allegations.

Production company JS Pictures issued an apology to the victim (a writer) and the cast and crew.

[11] The series was slated for release in the second half of 2019, but did not air until October 2021 for unspecified reasons.