The 'Person of Interest' team suffers a devastating loss and confronts staggering challenges in the hit series' most Explosive season yet. Adapting to the next evolution of The Machine, now completely self-governed and hidden from all, technical wizard Harold Finch (Michael Emerson) and ex-CIA operative John Reese (Jim Caviezel) team with rogue agent Sameen Shaw (Sarah Shahi) to save lives and seek justice. However, their missions now threaten to tear them apart. NYPD Detectives Joss Carter (Taraji P. Henson) and Lionel Fusco (Kevin Chapman) finally unravel the criminal police conspiracy "HR" - but at a tragic cost. And former cyber-enemy - and now highly tuned confederate of The Machine - Root (Amy Acker) becomes an unpredictable ally when the team learns a second surveillance apparatus to rival The Machine is on the verge of activation.