After the arson, Criminal Division Three is swamped with work. Son Woojoo and Shin Heemin look into the arson case, and Lee Jigwang and Jaechan reinvestigate the IV drip serial murder case. Hongjoo also begins to look into the case. Meanwhile, Yoobeom receives a mysterious text message from the real killer.

Hongjoo is injected with a lethal drug and loses consciousness. Fortunately, Jaechan comes just in time to save her. The court hearing begins and Hongjoo is summoned to testify.

Hongjoo is injected with a lethal drug and loses consciousness. Fortunately, Jaechan comes just in time to save her. The court hearing begins and Hongjoo is summoned to testify.