Plot summary
The Machine provides Reese a code that translates to the SSN of accountant Leon Tao, who is being targeted for stealing money from the Aryan Brotherhood. Reese saves Tao from the gang and adopts their dog, which he names Bear. The government sabotages Carter's investigation into Corwin's death to prevent her from learning about the Machine. Root takes Finch to a cabin in Maryland and kidnaps NSA operative Denton Weeks. She explains that she sees the Machine as a "perfect intelligence" and wants to "set it free." Reese threatens to quit his operations unless the Machine helps him find Finch, and receives the SSN of a girl in Texas who has been missing since 1991 when she was 14.
Flashbacks to the early days of the Machine's development depict it saving Finch from a distracted driver who dies in a crash. Finch rebukes the Machine and states that it should be protecting everyone, not only him.
Credits
Adapted from Wikipedia contributors, Person of Interest season 2. HTML formatting and reference markers removed.