After getting an officer suspended from service, Ryu Su-yeol gets a step closer to a promotion. Oh Gyeong-tae looks for a young girl's missing mom.

Su-yeol retraces Gyeong-tae's steps while tracking down the man in the helmet. Lee Hui-gyeom goes after a necklace that may hold crucial evidence.

After ensuring Gyeong-tae's safety, Su-yeol pulls a dirty move. With Kim Gye-sik back on the force, the narcotics unit tracks down a street drug.