Main •
Yunjin Kim as Ma Ji-won : A mystery writer. •
Jung Woong-in as Han Tae-kyu : A detective in charge of Ms. Ma's case. •
Ko Sung-hee as Seo Eun-ji : A woman who introduces herself as Ms. Ma's niece and then lives at her house. • Choi Kwang-je as Ko Mal-koo : A retired gangster who works as a loan creditor.
Recurring •
CNU as Bae Do-hwan : A young police officer stationed at the village where Ms. Ma and Eun-ji are currently staying. • Myung Gye-nam as Jang Il-koo • Song Young-kyu as Jang Cheol-min • Kim Young-a as Yang Mi-hee •
Sung Ji-ru as Jo Chang-gil •
Moon Hee-kyung as Madame Park • Hwang Suk-jung as CEO Oh •
Yoon Hae-young as Lee Jung-hee • Lee Ye-won as Jang Min-seo : Ms. Ma's deceased daughter. •
Choi Seung-hoon as Choi Woo-joon •
Lee Myung-hoon as Heo Joo Yeong ==Original soundtrack==