The location named Vault 81 is a Vault that is constructed by the Vault-Tec Corporation that’s in the Commonwealth. To be more exact it is a bit north-west of Chestnut Hillock Reservoir and south of Oberland Station.
Vault 81 background story
In a lot of ways Vault 81 is not like any other Vault that has been created. Vault-Tec Corporation have created this Vault 81 and its sole purpose is to develop a one universal cure for all of the sicknesses that humanity could suffer from. In this project, residents are being used as test subjects. The vault was divided in two areas where in one people were making a home and living there and the other a secret one where scientists would observe their experiment and watch residents as they exposed different diseases and later cures through propellant nozzles hidden in resident’s rooms.
However, the first vault overseer did not approve on testing on humans and using them as guinea pigs. Secretly she tried to think of a plan to end these experiments. Her name was Dr. Olivette. Long story short, she kind of figured it out and at the end locked three scientists in the secret vault with no chance to escape or to communicate with the outside world. The scientists – Kenneth Collins, Jim Flint and Burrow, while locked-in still kept working on a cure by testing mole rats.
The scientists created a lab assistant named Curie and when the scientists died of old age Curie kept working on the cure. After decades of perfecting the cure, in 2204, the cure was finally made.
In 2277 the vault was opened for the first time by its overseer Baht, that aloud communication and trade with the outside world. In 2287 one of Vault 81 dwellers Bobby De Luca found a way into the secret vault and used it as storage place for his drugs. When Bobby opened the volt, Austin Engill went in to investigate and was bitten by one of the mole rats that was still infected with various diseases and picked up a lethal disease. Bobby told everything to Sole Survivor and he discovered Curie who gave him the last existing dose of the universal cure. Now the Sole Survivor could use the cure on themselves or turn it over to save Austin and be given a room in the vault by Overseer McNamara as well as appreciation throughout the vault.
Vault 81 layout
Vault 81has to separate main areas – the regular vault where all the regular human residents live and the secret vault that is used for scientists to observe their human guinea pigs and conduct research. Later on, in 2287 the secret vault has been overrun by a unique breed of mole rats. The regular volt is still functioning at full capacity and no resident knows the truth of what has happened here so many years ago, inhabited by vault dwellers.
To get to the secret vault there are two entrances – an elevator that can be found in the lobby; a secret door that can be found in reactor room. Though the elevator can’t actually be used until a Hole in the Wall quest is completed and the door is connected to this quest as well because you can’t open them before the beginning of Hole in the Wall quest.
Hole in the Wall quest
To trigger Hole in the Wall quest you have to leave Vault 81 and walk a bit beyond the vault’s entrance – cave and then simply return to the vault. Go back to Doctor Forsythe and you will encounter a tense situation with vault dweller a sick child. You are their chance; they need a cure and it is located in a closed-off section of the vault. And after choosing to accept the quest – follow Bobby DeLuca he will lead you to the entrance of the secret vault.
There are not many surprises in this area, just a lot of mole rats, turns and stairs. When you see a robot that’s behind the glass, tell that you have come here to relieve her of her duties. The robot will be very happy and open the door and give you the cure. When you deliver the cure to Doctor Forsythe and a conversation with him the quest will conclude.