Before the Great War , Vault 4 was featured in advertisements and Vault orientation videos, with Cooper Howard serving as the spokesman. The Vault's experiment was publicly revealed in these advertisements: it would be governed by scientists living and working there full-time technocracy. Lloyd and Cassandra Hawthorne , two prominent researchers on the effects of radiation on DNA, as well as their two children and 80 other volunteers, signed up to live in the Vault for a five-year trial before the Great War to show that society would survive even in a Vault.
Lloyd Hawthorne eventually became the Vault's overseer after the Great War. Sealed on the day of the Great War , the Vault became a part of the Vault experiment, examining the performance of a society governed entirely by scientists with no limits on their control and decisions.
However, the Vault's governance by scientists led to unrestricted research, including human testing, which led to the scientists' downfall. Luring wastelanders into the Vault, the scientists subjected them to mutation experiments, including hybridizing humans with radiation-resistant species, leading to the creation of creatures such as gulpers. Subject giving birth to gulpers.
Each experiment was carefully recorded for analysis, including one of the victims of these experiments giving birth to a school of gulpers, who proceeded to eat her alive in the birth tank. The horrific nature of the experimentation led to a rebellion by the test subjects, [2] who unleashed the mutated victims on the scientists.
Overseer Hawthorne and his wife tried to barricade themselves outside the specimen laboratory, but the gulpers managed to break through the barricade, eating them both alive. In his final log, the overseer was unapologetic, insisting that hybridizing humans with radioactive-resistant species still had potential, as did a society governed entirely by scientists. In full control of the Vault, the former test subjects decided to use it for the betterment of humanity, establishing a democratic system and instituting a policy of accepting refugees from the outside world, turning them into Vault dwellers.
