Reese and Finch try to protect a psychologist whose unorthodox methods for helping his patients find closure could cost him dearly. Meanwhile, flashbacks reveal Finch’s fragile state in the days following the bombing that killed his best friend, Nathan Ingram.

The mysterious criminal mastermind known as “The Voice” returns and traps Reese and Fusco in their own precinct with several armed gang members and the latest POI. Also, Root makes a shocking discovery.