Due to their different approaches to crime solving, Dong-soo clashes with Hwang Shin-hye (Oh Yeon-soo), a profiler who recently returned to Korea after studying overseas.

Middle brother Jang Dong-chul (Kim Jae-joong) grew up as a petty thug on the streets, using his fists and wits to survive until he climbs to the top of a crime syndicate.

Youngest brother Jang Dong-woo (Im Si-wan) was adopted by a rich chaebol family, and now under the name Yoon Yang-ha, is being groomed as the heir to a casino empire.

Upon release, the two decide to embark on a mission to get revenge on everyone who has wronged them, including Dong-woo's father, Yoon Tae-joon, the CEO of Daejung Group and Go Bok-tae (Kim Byeong-ok), the gang boss who helped Yang-ha put Young-dal in jail.

Lead actor Kim Jae-joong's fan club in China has been broadcasting a total of 144 promotional screens at popular subway stations in Seoul since the 10th.