"A Thug" or "A Rogue") is a 2015 South Korean neo-noir crime drama film starring Jeon Do-yeon and Kim Nam-gil.

[9][10][11][12][13][14][15][16][17] The police are staking out Park Joon-gil for the murder of Hwang Choong-nam, and jaded detective Jung Jae-gon is being pressured to close the case, particularly by his former superior Moon Ki-beom, who lost his badge for corruption.

Joon-gil was once the mob enforcer for Jay Investment, but had fallen out of favor when he embezzled and stole the heart of Kim Hye-kyung, the girlfriend of the company's vice president Park Jong-ho.

Introducing himself as Joon-gil's former cellmate Lee Young-joon, Jae-gon begins to spend time with the suspicious Hye-kyung and gradually wins her trust.

[18][19][20] Lee Jung-jae was originally cast in the leading role as Jung Jae-gon, but dropped out after he was injured on the set of his 2014 film Big Match.