John Reese (Jim Caviezel), a former CIA agent and Army Special Forces soldier-turned homeless alcoholic, has a struggle with a group of hot-headed teenagers on the subway. After this, he is extracted from police custody, before Homicide Detective Joss Carter (Taraji P. Henson) can confront him on his links to previous killings discovered through analysis of his fingerprints on the police system. Reese is brought to a mysterious and somewhat secretive billionaire, Harold Finch (Michael Emerson), who is the creator of the next-generation software, "The Machine". After 9/11, Finch developed a computer program that can sift though enormous amounts of data, looking for patterns of behavior or activity that would predict another attack. It also provided information about individuals who could be in danger; it can predict the identity of a person involved in a premeditated crime that will happen at some point in the future – however, Finch's back-door link to the Machine only provides the Social Security number of the person, and offers no clues to their involvement or when the crime will take place. Finch, who needs to do something to help these people, enlists Reese to aid him in preventing these crimes. Finch offers Reese a job to do this, as well as give Reese a purpose following the death of his girlfriend, Jessica (which is the source of his depression). The first on his list is Diane Hansen (Natalie Zea), an Assistant District Attorney currently working on a major prosecution of a prominent drug killing. Reese agrees to help and begins by watching her. Reese soon learns that Hansen is not the victim, but the perpetrator, running a ring of corrupt police officers and planning to kill a fellow DA, Wheeler. After blackmailing one of the corrupt officers, Detective Lionel Fusco (Kevin Chapman), into being his source of information inside the NYPD, Reese reveals Hansen's corruption to an open court, kills the leader of the corrupt gang of cops, and links Fusco to the crime to ensure his future cooperation. Having previously rejected Finch's offer of work, Reese recants and agrees to continue preventing violent crimes.
