Also known as "Strangers from Hell".
Based on a Webtoon by Kim Yong-ki.
Character Yoo Ki Hyuk is not in the original webtoon.
Actress Ahn Eun-Jin made a cameo appearance in 2021 OCN drama series "Dark Hole" playing Detective So Jung-Hwa (same name as her character in "Strangers From Hell").
First acting role for Yim Si-Wan since being discharged from the South Korean military on March 27, 2019.