Han River Police

While on patrol, Han Dujin spots Go Giseok acting suspiciously and gives chase.

A ferry runs aground in the middle of the Han River. Despite the captain’s objections, Go Giseok attempts to steer the ferry out, causing it to tilt and nearly capsize. Han Dujin arrives on the scene and evacuates the passengers, but the rescue proves challenging due to the large scale of the incident. Baek Chul brings a barge to assist, but Dujin is reluctant to accept his help because of their troubled past. Later, Dujin’s team discovers Baek Chul’s barge tethered to the stranded ferry and suspects suspicious activity.

The team discovers Go Giseok and Baek Chul by the river ferry and is immediately suspicious; a falling oxygen tank hits Dujin's head and leaves him unconscious in the river.

Han Dujin and Lee Jungchan investigate several mysterious incidents in the Han River, including that of a murdered captain, and hope that Palmi Island will hold some answers; Hwang Mandae plans to use the river cruise business to smuggle gold.

Go Giseok kidnaps Han Dujin and Baek Chul's nephew, Han Jun; a furious Dujin becomes convinced that Giseok smuggled gold and that Baek Chul is involved; Lee Jungchan learns about the trade between Hwang Mandae and Madam Choi.

Han Dujin uses a GPS tracker to pursue Baek Chul, who has arranged to meet Go Giseok and exchange the remaining gold bars for Han Jun's return; Dujin interrupts the meeting and fights off Giseok's henchmen so Baek Chul can safely escape with Jun.