The team races to stop an active serial killer after three women are found weighted down at the bottom of a lake, and Jubal looks into an old closed case after there are multiple similarities to the recent victims.

After a man is killed by an explosive package shipped to his home, the team attempts to capture the sender and intercept his latest deadly parcel. Also, Maggie tries to trust her younger sister, Erin, is truly staying out of trouble as a new college student in NYC.