The series revolves around a computer program for the federal government known as "The Machine" that is capable of collating all sources of information to predict terrorist acts and to identify people planning them.
A team, consisting of John Reese, Harold Finch and Sameen Shaw follow "irrelevant" crimes: lesser level of priority for the government.
The title refers to "Deus ex machina", a plot device whereby a seemingly unsolvable problem in a story is suddenly and abruptly resolved by an unexpected and unlikely occurrence.
According to Nielsen Media Research, the episode was seen by an estimated 10.95 million household viewers and gained a 1.9/6 ratings share among adults aged 18–49.
However, he is pressured by the unknown person to put more effort in Vigilance and he convinces his group to retrieve more drives just to make sure their mission is accomplished.
Root (Amy Acker) gives an instruction to Reese (Jim Caviezel), Shaw (Sarah Shahi) and Hersh (Boris McGiver) to go to a location.
Greer (John Nolan) then tells Collier that his plan to expose them failed as the equipment they used was redirected to an office in the other side of the town.
Finch, Reese, Shaw, Root, Daniel Casey, Jason Greenfield and Daizo are given new IDs so Samaritan can't track them.
In its original American broadcast, "Deus Ex Machina" was seen by an estimated 10.95 million household viewers and gained a 1.9/6 ratings share among adults aged 18–49, according to Nielsen Media Research.
Matt Fowler of IGN gave the episode an "amazing" 9.5 out of 10 rating and wrote in his verdict, "'Deus Ex Machina' was commanding and shattering.
And while the entire trial may have wound up being even more of a farce than we originally expected, it was still an effective tension-builder that actually made me downgrade, in my mind, the level of Root's mission with Samaritan.
And finding out that our heroes' fates were already sealed after Reese and Shaw refused to kill the senator back in 'Death Benefit' really helped shed a light on how important that episode was.
But the season finale, which manages to sum up the past 23 episodes while hurtling toward the inevitable cliffhanger, reminds you that some of the worst monsters are motivated by what they see as patriotic ideals and noble goals.
"[5] Sean McKenna of TV Fanatic gave the episode a 4.6 star rating out of 5 and wrote "It's clear that Person of Interest isn't keen on the usual; its expanding of the mythos, elaborating on the characters and maintaining its charm and fun on top of an entertaining story, is still holding strong in the third season.