John McClane and a young hacker join forces to take down master cyber-terrorist Thomas Gabriel in Washington D.C.
The elevator shaft sequence was not in the film's script when Len Wiseman was hired as director. Wiseman added it because he associated elevator shafts and claustrophobic spaces with Die Hard (1988).
In the elevator shaft scene, where Mai Lihn swings on the wire, and flies into the truck and hits McClane, the stunt double accidentally cut Bruce Willis' eyebrow with her spiked heel, and according to Len Wiseman in the DVD commentary, she jabbed Willis hard enough that when medics examined the injury, the brow bone was exposed.
In addition to the 'Agent Johnson' reference, several other elements from the first Die Hard (1988) film are revisited as series trademarks. Among them are: crawling on broken glass, use of air-ducts, elevator shafts, and maintenance areas in corporate buildings, a henchman falling down stairs, an inquiry on the E.T.A. of a helicopter, and McClane's "Yippie-Ki-Yay' catchphrase, (heard in its uncensored glory in the unrated version).
Each film in the Die Hard series contains a key scene involving an elevator.
In the elevator shaft, when the guy gets hit by Matt and falls onto the back of the SUV and drops his weapon into the SUV, the steering wheel is missing, just after John drove drove it into the shaft in the prior scene.
When McClain grabs the cable that is hanging through the back glass of the SUV in the elevator shaft you can clearly see that the end of the cable is about 12 inches below his hand, but when the SUV falls McClain has about 10 feet of cable under him.
During the elevator scene when one of Mia's henchmen shoots through the rear window of the SUV we can see thousands of glass shards on and splintered on the back of the rear seat. However, when McClane proceeds to climbing out the rear after it was safe, the backs of the rear seats were perfectly clean, without a single piece of glass.
"A Farewell to Arms" by John Carlin
Characters by Roderick Thorp
Bruce Willis as Detective John McClane, who works for the New York City Police Department.
Justin Long as Matthew "Matt" Farrell
Timothy Olyphant as Thomas Gabriel, a former Defense Department analyst who leads a group of cyber-terrorists systematically shutting down the entire U.S. infrastructure. Olyphant filmed his role within three weeks.
Mary Elizabeth Winstead as Lucy Gennero-McClane, McClane's estranged daughter. The inclusion of McClane's daughter was previously considered for the third film, and she was in the video game Die Hard: Vendetta.
Maggie Q as Mai Linh, Gabriel's second-in-command and lover
Kevin Smith as Frederick "Warlock" Kaludis. Smith made uncredited rewrites to the scenes in which he appears.
Cliff Curtis as Miguel Bowman, Deputy Director of the FBI Cyber Security Division
Jonathan Sadowski as Trey, Gabriel's main hacker
Edoardo Costa as Emerson, Gabriel's henchman
Cyril Raffaelli as Rand, Gabriel's acrobatic henchman
Yorgo Constantine as Russo, Gabriel's henchman
Željko Ivanek as Agent Molina
Christina Chang as Taylor
Len Wiseman as the F-35B pilot (cameo)