The Vault of Nakatomi Plaza is the locked, highly-secured vault carrying $640 million of bearer bonds in the 30th floor of the Nakatomi Plaza. It has seven locks, which includes a code, five mechanical locks and an electromagnetic seal, which is controlled by the downtown Los Angeles power grid.
The bearer bonds inside the vault were a target of Hans Gruber and his men when they took over the building.
After Hans and his men took over the building, they tried to make Nakatomi head executive Joe Takagi reveal the code. But Takagi refused to give him the code, Hans executes him and has his computer expert Theo work on the vault. Theo says he can break the code around 30 minutes and he'll crack through the five mechanical locks on the vault in 2 to 2 1/2 hours at minimum. But as he opened the passageway that leads to the vault, he says the seventh lock, the electromagnetic seal, cannot be cut locally. Hans tells him Theo to trust him on that. With that, he and Kristoff began working on the vault.
As Theo cracked the code; which was Akagi translated into English: Red Castle, he began drilling the mechanical locks on it. As he drilled through two of the mechanical locks on the vault door, Hans checks in with him and Theo tells him his current status on the vault. After temporary stopping the drill for the moment and hear their intruder John McClane speaking to Sgt. Al Powell. After hearing McClane doesn't know about the vault, he re-activates the drill.
When the police were about to come in, Theo stops drilling the vault and monitors the Nakatomi security cameras. After the police backed off, Theo went back drilling the vault. After Hans made his fake demands to get the FBI to come, he checks in with Theo. Theo tells his leader that he has one more lock to go and the electromagnetic seal will take a miracle.
Meanwhile, Theo cracks the sixth lock in the vault and the electromagnetic lock was activated. Hans comes up and Theo shows him in the security monitors about the city engineers going through the street circuit and men in suits who he doesn't know. Hans tells Theo that those men are the FBI and they are ordering the city engineers to cut the building's power, which would deactivate the vault's electromagnetic lock. After the power grid is shut down, the electromagnetic lock disengages and the vault opens.
As Theo and Kristoff happily looked around the vault and pleased that they and the others are going to be rich, they began to load the bearer bonds into their bags. Then Hans and Eddie brought McClane's wife Holly over as leverage. As Theo left to get the ambulance ready to use as the escape vehicle, Hans, Eddie and Kristoff continue to load the bearer bonds into their bags.