Connection Season 1 Episode 1

Jang Jaegyeong is the Anhyun Police Station's Narcotics Unit's ace. One day, while pursuing drug dealers, Park Joonseo, a friend who hasn't been in contact for 20 years, comes to visit him. The following day, Joonseo's cold body is discovered, and Jaegyeong gets abducted and forced to become addicted to an unknown drug.