Three years after the synthetic drug case roundup in Korea, beast cop Ma Seok-do (Don LEE) and Metro Investigations are busy chasing down criminals who are dealing drugs through a delivery app, when the app distributor is found dead in the Philippines. The team soon realizes that this case involves a huge illegal online gambling business. In the Philippines, ex-special forces mercenary Baek Chang-gi (KIM Moo-yul) monopolizes Korea’s illegal online gambling business by means of abduction, confinement, assault, and even murder. Meanwhile back in Korea, IT genius CEO Chang Dong-cheol (LEE Dong-hwi) is hatching even bigger plans. Detective Ma reaches out to Jang I-su (PARK Ji-hwan) for help, and with support from the Cyber Investigations team, Metro Investigations begins to roundup some criminals… No borders, no turfs in rounding up crime– Upgraded crime-busting action! Ready to wipe ’em out again!