Secret Vault 81 is a hidden location within the main vault, which you can access during quest Hole in the Wall. This part of the vault is destroyed and infested by molerats. The location is quite big, but the major part of it is the long corridor.
1. There is a terminal here (novice), which activates the robot.
2. In the wall of the room, there is a master safe.
3. The door to the other part of the underground complex. You can open it using the expert terminal or by finding the password .
4. On the desk of this room, there is a password to the door to the next part of the lab . Right next to it, on the next desk, there is a Stealth-Boy, and in the fridge, you can find a lot of meds.
5. In the flipped cupboard, there is a mininuke. On the bed, there is a special crate painted in Vault 81 colors.
6. Here, you encounter Curie, who can be your new companion. As soon as you approach the glass, she talks to you and after a short conversation, she opens the door. Inside, you find Medicine Bobblehead.
7. The lift that takes you to the main part of Vault 81.