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.
According to Nielsen Media Research, the episode was seen by an estimated 12.23 million household viewers and gained a 2.0/6 ratings share among adults aged 18–49.
Reese (Jim Caviezel) and Shaw (Sarah Shahi) watch as Maria meets with a man, whose brother Omar Risha (Haaz Sleiman) has been arrested for terrorism, and gives her a package.
Later, Shaw and Fusco (Kevin Chapman) see Maria put a GPS tracker on a limo belonging to French United Nations diplomat Rene Lapointe (Michel Gill).
Finch (Michael Emerson) visits Omar in jail and learns that the generators were shipped elsewhere and that HydralCorp's corrupt CEO Ken Davis (Casey Biggs) is responsible.
In its original American broadcast, "Allegiance" was seen by an estimated 12.23 million household viewers and gained a 2.0/6 ratings share among adults aged 18–49, according to Nielsen Media Research.
Matt Fowler of IGN gave the episode a "great" 8 out of 10 rating and wrote in his verdict, "This week's POI case had the good fortune of being somewhat connected to the larger story, making it so that Root's side mission converged with the rest of the team's actions.