Plot summary
Reese must protect Charlie Burton, a schoolteacher who witnessed a Russian mobster shooting an Italian-American mob lieutenant in a Brighton Beach bodega. As Reese and Burton flee the Russian mob as well as the Five Families of New York's Italian mafia, they stumble into territory controlled by the Bulgarian mob. Meanwhile, Carter searches for Burton to place him in protective police custody, and in doing so, draws closer to finding Carl Elias, believed to be the illegitimate son of an aging mobster with a plan to unite the Five Families and reclaim the New York underworld from the Russians. Cut off from Finch as he tries to evade the Russians and Bulgarians, Reese comes to realize that Burton is Elias. Elias thanks Reese for saving him, but warns him not to interfere with his future goals, leaving Reese feeling guilty for endangering others by saving Elias' life.
Credits
Adapted from Wikipedia contributors, Person of Interest season 1. HTML formatting and reference markers removed.