Contains spoilers for this episode and earlier episodes.
At the underpass, Vincenzo learns the name Jang Han-seok but cannot yet connect it securely to Joon-woo. A vibrating phone almost exposes the intern, who produces a different handset to keep his disguise intact. Vincenzo and Cha-young interrogate the captured killers about the recent murders, using the same suffocating conditions inflicted on the victims' relatives. The men are then killed, crossing the boundary Cha-young once wanted their partnership to observe.
Babel counters with evidence of Vincenzo's Mafia work, leading prosecutors to arrest him during a tenants' game of Mafia. The residents discover that the role they jokingly assigned him is his actual background. An Ki-seok intervenes through the intelligence service, takes custody of Vincenzo and reveals the investigation he has been conducting. He now wants to join Jipuragi's fight, bringing resources the lawyers need to identify the man who supplied Babel's information.
Vincenzo asks Luca in Italy for help locating that informant, then uses the resulting lead to question him about the chairman. The answer finally links Jang Han-seok to Cha-young's former intern. Cha-young receives the warning while sitting opposite Joon-woo and manages to hide her reaction. After he returns home, he finds Vincenzo waiting with a gun aimed at his head. Joon-woo dares him to fire, and the episode ends with a gunshot before the outcome of their confrontation is shown.