After setting off anthrax alarms in many Government buildings, Emerson and his men enter the Woodlawn facility disguised as HAZMAT agents. They then kill the MP guards to gain access to the servers holding their desired data. Emerson enters the code to enter the server room and begins a download from the servers to his portable hard drives.
Rand the French assassin and the rest of the men on the semi-truck arrive in Woodlawn. Gabriel then instructs Russo to kidnap Lucy McClane, the daughter of John McClane and bring her to the facility. When John McClane and hacker Matt Farrell arrive, they trip the alarms originally designed to alert the FBI. Russo then arrives and threatens McClane and Farrell. McClane manages to overpower and toss Russo down a flight of stairs, but Farrell falls into a cooling tower vent.
McClane confronts the injured Russo asking him to disclose the location of his daughter Lucy, but Russo refuses to answer his request. Gabriel then attempts to check in with Russo, but ends up hearing McClane taunt him with a joke that Russo is on his way to meet with Gabriel's dead girlfriend, Mai Linh. Russo attempts to disclose McClane and Farrell's location, but is stopped when McClane fires a shot away from him (simulating shooting Russo) to scare Gabriel and state that he is coming for him. McClane then takes Russo's Beretta Px4 Storm pistol and leaves him in the stairways. Gabriel, outraged by the situation, sends Rand to kill McClane.
Farrell kicks open a nearby vent and attempts to navigate through the cooling ducts. After Emerson leaves the server room to check out one of the cooling towers that Farrell faked as failed, Farrell reaches to the room where he recognizes the security lock at the entrance to the server room as his own algorithm he indirectly passed to the cyber-terrorists. He then gains access to the room and sees that Gabriel and the others are going after the government's money. Farrell in a last ditch attempt to stop the terrorists, encrypts the data being downloaded. However, during the encryption process, Emerson returns and tells Farrell to put his hands up -- however, Farrell has already encrypted the system to the point that he must remain alive if the terrorists ever wish to retrieve the data.
McClane navigates the facility to get to Lucy while Gabriel and McClane speak to each other on the radio. When Gabriel's attempts at convincing McClane to stand down fail, he tries to make Lucy do so. However, Lucy only tells her father that "only five of them" remain. Angered, Gabriel slaps Lucy in the face and tells his surviving men to kill McClane. Suddenly, the elevator doors open and Emerson brings Farrell to Gabriel and informs him that Farrell has encrypted the laptop that contains the financial data they downloaded. Gabriel's lead (and surviving) hacker Trey states that it would take time to decrypt the data. Gabriel then has his men take Lucy and Farrell to leave the facility.
McClane goes to one of the cooling towers. As he is taunting Gabriel and asking him what he wants on his headstone through the radio, Rand fires at him from below. McClane refers to Rand as a hampster, who is easily avoiding gunfire. Rand jumps to McClane and kicks him off the bridge. As McClane falls near the deadly cooling device, he attempts to reach for the Beretta Px4 Storm pistol near the ice-cold nitrogen pipe, Rand gracefully jumps down and grabs the pistol, then fires at McClane. As Rand is climbing up, McClane activates a nitrogen valve causing Rand to fall into the cooling device, killing him immediately.
As Gabriel and the others take Lucy and Farrell to the HAZMAT van, McClane sees them taking off. As the tractor-trailer, driven by Robinson, follows the HAZMAT truck, McClane goes up to the balcony area and jumps on top of the truck. McClane eventually commandeers the truck to go after Gabriel and retrieve Lucy and Farrell.