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.

After a young girl is kidnapped from her daycare, the team must help her parents navigate a debt owed to the deadly gang in their neighborhood; Maggie struggles to focus on the case when her sister returns from rehab.

A drug dealer is shot in a federal park and the team sets out to look for his killer; Maggie's sister returns to New York and complicates the case.