Nam Gi Jun was once a key member of the Bongsan Gang, led by Koo Bong San. He fought through bloody turf wars, helping the gang rise to power. But everything changed when his younger brother, Nam Gi Seok, joined their rival gang, Joowoon, under Lee Ju Un. To protect his brother, Nam Gi Jun made a brutal choice - he left Bongsan for good, severing his left Achilles tendon as proof that he would never return. Eleven years later, he lives a quiet life, running a small drink supply business serving Bongsan-owned establishments. He has no intention of going back. But when Nam Gi Seok, now the second-in-command of Joowoon, is found dead under suspicious circumstances, Nam Gi Jun knows he can't stay away. To find the truth and take revenge, he steps back into the underworld he swore to leave behind - where old grudges still burn, power has shifted, and nothing is as it seems.