On the series premiere of Person of Interest…
John Reese, a man who lost purpose in his life is arrested after fighting a group of men.
After being released, he is approached by a mysterious and wealthy man named Finch. Finch reveals that he has a list of social security numbers that connect people to violent crimes. The numbers don't reveal if the person related is the victim or the perpetrator.
He offers Reese a job in preventing these murders.
Reese takes the job and his first "person of interest" is a female prosecutor named Diane Hanson.
At first, it is believed that she will be the victim, but Reese learns that she is working with a group of dirty cops.
Reese saves Hanson's target, a fellow prosecutor named Wheeler.
Reese's handiwork attracts NYPD Detective Carter as well as Detective Fusco, whom he used earlier to help him while he observed Hanson.
Reese agrees to continue to work with Finch and use the numbers created by The Machine to prevent crime.