Main •
Kim Hee-sun as Eulji Hae-yi, a beautiful but manipulative lawyer who has a 100 percent success rate in court. •
Kim Hae-sook as Jang Hwa-sa, a death-row convict who is the infamous killer behind a poison murder case. •
Kim Young-kwang as Gi Yoo-jin / young (real) Gi San, Hae-yi's boyfriend who is a family doctor. He seems to be smart and gentle but he hides an inner dark side.
Supporting •
Lee Geung-young as Gi San, Yoo-jin's half-brother who hides a secret from his past. •
Oh Dae-hwan as Oh Bong-sam, an investigator. •
Kim Jae-hwa as Kam Mi-ran • Jung Won-jong as Ma Hyun-chul • Min Sung-wook as So Young-chul
Special appearance •
Yoon Park as Chu Young-bae •
Song Yoon-ah as Park Hyun-jung ==Original soundtrack==