After her parents are murdered, a young woman awakens from a coma with total amnesia, and crosses paths with a cop who suffered a loss of his own.

Choi Moogak agrees to help Oh Chorim with her comedy skit in exchange for assistance on a case that could earn him a spot in the Violent Crimes Unit.

Chorim leads Moogak to a body in the river and is later followed. Moogak reveals to Chorim how he lost his sense of pain, taste and smell.

A new barcoded body is found, but Lt. Yeom Mi suspects it's a copycat killer's work. An accidental injury brings Chorim to Dr. Cheon Baekgyeong.

When a strangled chef falls off a roof, Kwon Jaehee becomes a suspect, but a scent leads Chorim elsewhere. Moogak learns why Baekgyeong went to Jeju.

A confession letter is written and stored. Joo Mari's journals are discovered. Moogak figures out what the barcodes on the victims' bodies signify.

The Barcode Killer places the next body so it will be found and covers his tracks. Chorim's friend Ma Aeri is accused of stealing from her employer.

Moogak is rushed to the hospital, where the police set a trap for his attacker. The Barcode Killer decodes his last victim's cryptic final message.

Moogak lures the Barcode Killer using fake medical records and a decoy Choi Eunseol. Mi creates a police sketch of the woman Chorim remembers.

Mi follows her hunch about Chorim, who has a flashback to the moment of her accident. The misplaced confession letter is found among some books.

Moogak snoops in Mi's office and learns why she took him off the case. The Barcode Killer visits Chorim's dad to find out who the witness is.

Chorim manages to escape from the Barcode killer, who steals a photo from her father's home address in order to identify her.

Chorim reveals her special ability to the entire Violent Crimes Unit. The Barcode Killer uses the witness's old school friends to lure her into a trap.

When the police are unable to find the secret room where Mi is being held, Chorim contacts the Barcode Killer and volunteers to take her place.

The Barcode Killer makes a run for it. Chorim remembers more about her parents and the day of her accident. A romantic gesture backfires on Moogak.

The Barcode Killer abducts Chorim in order to lure Moogak into a deadly trap, but Chorim leaves behind a clue that could save his life.