Immediately after coming off a suspension, Detective So-yung (Yoon-ah Song — Face) is thrust into one doozy of a case. Seems the victim died from acid. An acid released from inside his body. And this isn't the type of acid those crazy kids are fond of — the only trip these cats are taking is to the morgue.To make matters worse, there are a couple more men dying off the same way. There appears to be a serial killer on the loose, and the last thing the victims are seeing is a long-haired woman in black (with some freaky blood-shot eyes).Throw in a new partner and some crazy dreams and So-young has her work cut out for her.