"You are being watched. The government has a secret system, a machine that spies on you every hour of every day. I know because I built it. I designed The Machine to detect acts of terror, but it sees everything. Violent crimes involving ordinary people, people like you. Crimes the government considered "irrelevant". They wouldn't act, so I decided I would. But I needed a partner, someone with the skills to intervene. Hunted by the authorities, we work in secret. You'll never find us, but victim or perpetrator, if your number's up... we'll find you."Person of Interest is a science fiction action-thriller TV series that started airing in September 2011 on CBS. It was created by Jonathan Nolan and developed along with J. J. Abrams and Bryan Burk. Prior to airing, it was much-hyped for the strong pedigree of cast and crew, and later the pilot received positive reviews. The show aired five complete seasons, wrapping in June 2016.John Reese (Jim Caviezel) is a former CIA agent, reduced to living rough as a drunk homeless man in New York City after a falling-out with the United States government. He's bailed out of trouble with the NYPD by a mysterious billionaire named Harold Finch (Michael Emerson), who has a strange and potentially dangerous job offer. As it turns out, Finch is a software genius who designed the government supercomputer—"The Machine"—that monitors all surveillance and computer data, analyzing and filtering it in search of persons involved in potential threats to national security. When The Machine identifies one of these individuals, it transmits their Social Security number to the government.As a side effect, The Machine also spits out "irrelevant" numbers that correspond to someone that it predicts will soon be involved in a violent crime which is not relevant to national security. To help these potential victims (or to stop these potential killers, as the case might sometimes be), Finch hires Reese, and together, they use their collective skills and resources to help innocent people.In the process, they cross paths with two NYPD detectives: Joss Carter (Taraji P. Henson), who is initially an antagonist, investigating a number of violent incidents involving a mysterious "man in a suit" (Reese), but later begins cooperating with Reese and Finch; and Lionel Fusco (Kevin Chapman), an ambiguously corrupt cop who Reese ropes into helping him and Finch, helping him to redeem himself for his past crimes along the way.Rounding out the cast of weekly rogues and "irrelevant numbers" is an ensemble of recurring characters, many of whom are important to the longer story arcs:
— Harold Finch, Season 1 Opening Narration
- Zoe Morgan, a "fixer" who trades in favors and information with the city's elite and flirts with Reese.
- Carl Elias, an elusive mob boss and master criminal, ruthless yet also honorable, whose conspiracies and criminal enterprises have generated several POI numbers.
- "HR", a network of corrupt NYPD cops and politicians which, at different times, has both opposed and supported other crime syndicates such as the Russian mob and Elias' organization.
- "Root", A.K.A. Samantha Groves (Amy Acker), a master hacker obsessed with The Machine who later becomes its "analog interface".
- Grace Hendricks, Finch's former fiancé, who believes he is dead.
- Northern Lights, the government program that deals with Relevant threats identified by The Machine, and is ruthless in suppressing all knowledge of The Machine. It often acts through personnel from other government agencies, including figures from Reese's time with the CIA.
- Leon Tao, an accountant with a penchant for getting into trouble.
- Bear, a trained military dog.
- Sameen Shaw (Sarah Shahi), a Distaff Counterpart to Reese.
- Decima Technologies, a shadowy private intelligence organization based in China which tries to control The Machine, and later attempts to bring their own supercomputer, Samaritan, to life.
- Vigilance, a group of people opposed to the lack of personal privacy caused by government and corporate data mining actions, who became radical enough to start killing the people they considered the most egregious offenders.
- The Brotherhood, a tech-savvy street gang that moves to take over the drug trade in New York.
- "Harper Rose", a skilled grifter.