John McClane, a New York City/Los Angeles police detective, continually finds himself in the middle of violent crises and intrigues where he is the only hope against disaster.
An NYPD officer tries to save his wife and several others taken hostage by German terrorists during a Christmas party at the Nakatomi Plaza in Los Angeles.
On Christmas Eve 1990, two years after Die Hard, police officer John McClane is waiting at Washington Dulles International Airport for his wife John McClane#Holly Gennero to arrive from Los Angeles. Reporter Richard Thornburg, who exposed Holly's identity to Hans Gruber in the Nakatomi Tower, is assigned a seat across the aisle from her. In the airport bar, McClane observes two men in Army fatigues behaving suspiciously and pursues them into the baggage area. After a shootout, McClane kills one man while the other escapes. Learning that the dead man is an American soldier believed to be killed in action while originally serving in Honduras, McClane relates the situation to airport police captain Carmine Lorenzo, who in his arrogance dismisses any concerns.
In New York City, John McClane, a cop is targeted by notorious German terrorist Simon Gruber, where he plans to rob the Federal Reserve Building.
The Federal Bureau of Investigation responds to a brief computer outage at its Cyber-Security Division by tracking down top Hacker (computer security) who had been on a watch list. The FBI asks New York City Police Department detective John McClane to bring in Matthew "Matt" Farrell, one of the hackers. McClane arrives at Farrell's residence just in time to save Farrell from assassins working for Mai Linh, who works for her love interest, Thomas Gabriel.
In Moscow, Viktor Chagarin, a high-ranking, but corrupt, Russian official plans to incriminate former billionaire and government whistleblower Yuri Komarov in an imminent rigged trial unless Komarov hands over a secret file believed to contain evidence incriminating Chagarin. Separately, Jack McClane, who has been arrested after an assassination attempt, negotiates for a shorter sentence by offering to testify against Komarov. Meanwhile, Jack's father, NYPD Detective John McClane, who has not been in touch with his son for several years, has learned his son is in trouble and, taken to the airport by his daughter Lucy McClane, flies to Russia to help. As John arrives and approaches the courthouse where Komarov is on trial, a bomb explosion, orchestrated by Chagarin's henchman Alik, occurs in the courthouse and Jack breaks free with Komarov. Seeing his son, John confronts him, but their dispute is cut short as Alik and his men chase them in a US Cougar (vehicle) MRAP through the streets of Moscow. John, Jack, and Komarov manage to escape.