Plot summary
Martine engages in a gunfight with Shaw, who ultimately escapes thanks to Root. Martine learns that Fusco had stopped the truck that Root and Shaw used to escape, on a suspicion of Narcotics possession. Pretending to be a DEA agent, Martine questions Fusco about it, but he sees through the ruse and gives her a false lead. Reese and Finch deal with their latest number, Elias. Dominic gets many of Elias's people to turn on him in exchange for promises of expanded territory and power under The Brotherhood. Reese steps in to defend Elias and, during the process of evading Dominic, Anthony is captured and later killed in a suicide bombing.
Greer and Martine deduce that Samaritan has a "blind spot" somehow caused by The Machine. Martine is given command of a group of Decima agents to hunt down Shaw. Meanwhile, Dominic has deduced that there is an extra-legal team helping Elias—he has two of the players figured out (Shaw and Reese), with the bankroller's place (Harold) still a large question mark. Elias vows revenge for the death of Anthony, and warns Reese to stay out of the way once that day comes.
Credits
Adapted from Wikipedia contributors, Person of Interest season 4. HTML formatting and reference markers removed.