Sam, Bailey, Grace, and Nathan are taunted by a diabolical female serial killer who prefers to use a variety of exotic poisonous animals, (tree frogs, spiders, snakes, etc.) to kill her victims, while providing her pursuers with cryptic clues to her next murder. Meanwhile, John, now back working for the Atlanta police, arrests Francis during a drug raid and tries to talk some sense into her. A frustrated Bailey is further irritated by the arrival of a sexy private investigator, named Christine Logan, who tries to aid the VCTF, but it's the unit's chief nemesis, a jealous Jack of All Trades, who ironically can help the most when he sends fax messages to Sam of clues to the killer's identity. Also, Bailey asks Cooper to replace John on the team while Brubaker decides on a transfer.