4C, while literally Reese's seat number, is also a play on the word "foresee", that is, to anticipate a coming event. In this story, Reese, having said goodbye to Finch and broken down his telephone, expects to travel to Istanbul to put his life behind him. What Reese does not foresee is the Machine's determination to give him a reason to return to Finch, and its influence, even on a plane in flight.
VoIP (Voice Over Internet Protocol) is a technology that enables communication and multimedia sessions to other parties via connection to the internet. Communication services (voice, fax, SMS, voice-messaging) are converted from analog audio signals into digital data that can be transmitted over the internet.
The film playing on the main screen in first class was Alfred Hitchcock's 1959 classic, "North by Northwest". The film stars Cary Grant and Eva Marie Saint. A reference to the film was previously made in "Zero Day" with the Machine's alias Ernest Thornhill. The name of the lead character played by Cary Grant is Roger O. Thornhill and the name of the writer of film is Ernest Lehman.
The drug Shaw used on Hersh was scopolamine, a drug generally used for motion sickness, which in larger doses has been used as a truth serum. Hersh was easily able to identify it because of the recognizable, and unpleasant, side effects that accompany the dose he was given.
This episode features the use of the green triangle, which the Machine uses to mark and identify commercial aviation traffic. The Machine tags planes in flight with their flight number and IATA codes for the departure and destination cities, in Reese's case ZA427 JFK-FCO. It also introduces a red triangle, used to identify a flight in imminent danger.
Reese's flight lands at Fiumicino - Leonardo da Vinci Airport (IATA airport code: FCO), Rome's principal international airport. Rome is a common hub for flights to the Middle East and Balkan regions, such as Reese's onward flight to Istanbul. His flight departs on December 21, 2013 at 15:20 (3:20 pm in New York or 9:20 pm in Rome.)
The Machine calculates the probability of Reese's death at over 26%. By contrast, it estimates the likelihood of the situation resolving itself at less than 1%.
The Machine Object ID in the picture provided is: 313.012.010.AC0E.2., which is unique from other Machine Object IDs.
Bitcoin, a real-world digital currency, is also mentioned in this episode.
Finch suggests that they arrange for Reese to have his suit made by Finch's favorite tailor at Gianni's atelier. An atelier is the small workshop of a master of the arts; in this case it would be Gianni's small shop rather than a larger clothing store. Although the term is traditionally associated with the decorative arts, it has come to be associated with custom (versus designer) clothing in parts of Europe. In Italy, there are numerous small tailor's and shoemaker's shops, each crafting made-to-order goods.
The configuration of seats in coach (2-4-2) and exterior views indicate the plane on which Reese is traveling is a Boeing 767. However, when we see the seating chart as the Machine assesses the situation, the coach seating is in the 2-5-2 configuration of a Boeing 777.
The plane decreases from 32,000 feet to around 1,500 ft in less than three minutes. The Machine states that the descent rate is -1000ft/min. At this rate of descent, the plane should have taken 30-31 minutes to descend.
In the opening segment, the flight information screen that Reese walks past shows that several of the flight numbers in the Arrivals section have been inadvertently scrambled and do not match the names of the airlines.
"Whoa! What's with the conspiracy theories, Mr. Dark and Stormy?" (Owen, to Reese)
"You seem like an angry guy. Do you want to talk about that? I really think you want to talk about that." (Owen, to Reese)
"Hey, I don't mean this the wrong way, but who the hell are you?" (Owen, to Reese)
"Your hair looks fine. That salt and pepper thing is like catnip to soccer moms" (Owen, to Reese)
"I thought you got rid of that walking steroid?" (Owen, to Reese)
"I always liked you Hersh. Even after you killed me." (Shaw)
"Shaw, your new employers - are they treating you okay?" (Hersh)
"While I'm in Italy, I thought I would get fitted for a new suit." (Reese)
"Mr. Reese, I understand your frustration with the opacity of the Machine, but there is a reason I chose to make it that way. The Machine only gives us numbers because I would always rather that a human element remain in determining something so critical as someone’s fate. We have free will, and with that comes great responsibility, and some times great loss. I miss her dearly too..." (Finch, to Reese)