Nam Sang-mi plays widowed police officer Lee Sun-ae who finds herself suddenly immersed into international espionage by Han Yoo-il (Dennis Oh), an undercover agent. Lee Joo-hyun plays Kang-Jun, who's recently transferred to the Criminal Investigation Department. He opens an old case involving Sun-ae's past that leads him to an entanglement between the current political/economic powers and their secrets. One of them, oddly enough, being Han Yoo-il. Who is this man? Why is he here?

Public Safety Station

    Nam Sang Mi is Lee Soon Ae (Officer)
    Jung Jong Joon as Sgt. Hong Kyung Jang

Police Station

    Lee Joo Hyun is Kang Joon (new captain)
    Yoo Sun is Park Eun Joo (Officer)
    Kim Ha Kyoon as Lt. Jo Jung Hae
    Kim Bo Sung is Detective Shim
    Ahn Yeon Hong is Officer Oh Na Ra
    Yoon Joo Sang as the commanding officer

Joong Ang Gymnasium

    Choi Bool Am is Choi Bum Koo
    Lee Ki Yeol as Wang Sa Bal (Big Bowl)
    Kim Joon Ho as Kaori (Stingray)

Other people

    Dennis Oh is Han Yoo Il (investor)
    Ki Joo Bong as Yoo Il's assistant
    Sung Eun as Choi Ji Soo (actress)
    Kim Il Woo as Song Hyun Chul (Jang's Uncle, investor)
    Kim Yong Hee as Park Sil Jang (politician)
    Kim Min Jong
    Jung Hwan
    Park Jung Woo

    Chief Producer: Choi Chang Wook
    Director: Go Dong Sun
    Screenwriter: Kim Ki Ho, Lee Sun Mi
    Author: Kwon Mi Kyung