Bradberton's office is located in Nuka-Town USA, across from The Parlor. It can only be entered after finding the ten Hidden Cappy clues during the quest Cappy in a Haystack. Once all are found, return to Sierra Petrovita, who will decipher the passcode that unlocks the front door.
The first floor contains a small reception lobby and the stairway leading up to John-Caleb Bradberton office. Searching his office reveals a button behind the Nuka-Cola machine in the corner. Once pressed, a bookcase will swing aside, exposing a hidden elevator that leads down to Bradberton's private vault.
The vault consists of an entryway and a single room, where the preserved head of Bradberton is found, being kept alive by machinery and computers. To the right of Bradberton is the prototype storage room, which can only be unlocked if choosing to side with Bradberton and end his life.
In the upstairs office:
- General Braxton's visit - Holotape, in the expert-locked safe (the key is on a table in the prototype storage room in the secret vault).
- Nuka-Cola Clear - Holotape, on the desk.
- Nuka-World contest flyer - On the desk.
- Nuka-World jumpsuit - Reward for Cappy in a Haystack, given by siding with Sierra.
In the secret vault's prototype storage room, accessible only if the power is cut during Cappy in a Haystack:
- Inside the vault is a mint condition Chryslus Cherry Bomb and Lone Wanderer motorcycle.
- After cutting the power to end Bradberton's life, his eyes will remain open and periodically look side to side.
- Noclipping with console commands reveals that the vault door is marked Vault 111.