1x9 - A Bona Fide Killer

Sergei, Bo-na's childhood friend and a mercenary from Russia, reappears, and the truth of The Gosiwon Case in Haegong-dong from four years ago begins to surface. Bo-na investigates Sergei's return to Korea. Meanwhile, Dong-jin learns that Jang Eun-hak, the culprit who murdered his parents, has been paroled.