StemeMcPhie
First time out of the vault

This video takes a look at what the main plot would have been in Van Buren, Interplay's cancelled version of Fallout 3. While none of the content featured in Van Buren is absolutely cannon, this video is a good starting point for those who wish to learn more about what could have been.
TL;DW: The video tells you Van Buren would have taken place in 2253, or just 11 years after Fallout 2, in the Great Midwest Commonwealth. The player (titled "the Prisoner") would have woken up in an unfamiliar prison facility. During, an attack on the prison would be taking place, led by a Dr. Victor Presper. After escaping through a hole in their prison cell, the Prisoner would be free to explore the wasteland (albeit constantly being pursed by the prison's robotic caretakers, who wish to return them to the prison.)
The Prisoner would eventually discover that they have contracted the New Plague (a pre-war bioweapon developed by the Enclave, and the virus that FEV was intended to cure). The robotic caretakers of the prison are simply trying to quarantine the player in an attempt to stop the plague from spreading. Unfortunately, the robots' efforts are rendered futile as any location already visited by the Prisoner have already been infected.
To analyze and possibly treat the New Plague, the Prisoner would have to find information located inside of the aforementioned prison facility. However, the prison is in a state of lockdown due to the recent attack, and in order to gain access to the information the Prisoner would have to bring 7 of the escaped inmates (including theirself) back to the prison facility.
After doing so, the player would discover the true reason behind the prison and the attack on it. It turns out that, through extensive research, the mad scientist called Presper, disgusted with what the world turned into after the War, discovered the history of New Plague and its genocidal potency, and also discovered a viable means to cleanse the world. Using the quarantine prison, the prison's advanced A.I. named ODYSSEUS, and a connected ballistic satellite, the way to human planetary domination and order became clear. He needed to get to the ballistic satellite and use the nuclear weapons to clean the filth and wretch that currently have occupied the surface.
Presper and his followers released the New Plague virus in the remote areas near Boulder and Denver. It was close enough to the quarantine prison to spur ODYSSEUS into action, but not near enough to cause huge populations to start a general panic. Once enough people were infected and ODYSSEUS “arrested” enough people to just about fill up the prison, Presper’s men would stage an attack on the prison which would allow everyone to escape. This event would start a countdown of sorts for missile launch on the ballistic satellite. ODYSSEUS would assess the viral spread, try to gather up the escaped prisoners, and, once 90% of the prisoners had been retrieved, launch nuclear missiles to “clean & prevent” any further infection. By the time this happened, Presper had planned to be on, and in full control of, the ballistic satellite and reprogramming targeting solutions to clean the areas he wanted. Humans of his choosing would wait out the second nuclear holocaust in the Boulder Dome, until the day came where he declared the Earth safe for pure blood humans once more.
The Prisoner would then be able to repair and then use a spaceship to infiltrate the ballistic satellite. From there, the Prisoner would decide which course to take. Would they buy into Presper's vision of a new, better world, or would they put an end to Presper's plan by neutralizing the scientist and stopping his missiles? Alternatively, the Prisoner could use those missiles to settle some grudges of their own.
The video then goes on to talk about how there seems to be a general misconception about the storyline in Van Buren. New Vegas did take some clear inspiration from Van Buren, but for the most part the events in New Vegas would have occurred after the events of Van Buren. In many ways, New Vegas represents the storyline that would have been featured in the version of Fallout 4 that Interplay was planning.
TL;DR: The player is sick and in quarantine. The player escapes and infects many. The player wishes to have a better understanding of the cure and through doing so finds out a mad scientist is responsible for getting people sick in order to for most people to die. The player confronts the scientist in space and either a) teams up with the scientist and most people die or b) stops the scientist and (at the very least) some people die.
TL;DW: The video tells you Van Buren would have taken place in 2253, or just 11 years after Fallout 2, in the Great Midwest Commonwealth. The player (titled "the Prisoner") would have woken up in an unfamiliar prison facility. During, an attack on the prison would be taking place, led by a Dr. Victor Presper. After escaping through a hole in their prison cell, the Prisoner would be free to explore the wasteland (albeit constantly being pursed by the prison's robotic caretakers, who wish to return them to the prison.)
The Prisoner would eventually discover that they have contracted the New Plague (a pre-war bioweapon developed by the Enclave, and the virus that FEV was intended to cure). The robotic caretakers of the prison are simply trying to quarantine the player in an attempt to stop the plague from spreading. Unfortunately, the robots' efforts are rendered futile as any location already visited by the Prisoner have already been infected.
To analyze and possibly treat the New Plague, the Prisoner would have to find information located inside of the aforementioned prison facility. However, the prison is in a state of lockdown due to the recent attack, and in order to gain access to the information the Prisoner would have to bring 7 of the escaped inmates (including theirself) back to the prison facility.
After doing so, the player would discover the true reason behind the prison and the attack on it. It turns out that, through extensive research, the mad scientist called Presper, disgusted with what the world turned into after the War, discovered the history of New Plague and its genocidal potency, and also discovered a viable means to cleanse the world. Using the quarantine prison, the prison's advanced A.I. named ODYSSEUS, and a connected ballistic satellite, the way to human planetary domination and order became clear. He needed to get to the ballistic satellite and use the nuclear weapons to clean the filth and wretch that currently have occupied the surface.
Presper and his followers released the New Plague virus in the remote areas near Boulder and Denver. It was close enough to the quarantine prison to spur ODYSSEUS into action, but not near enough to cause huge populations to start a general panic. Once enough people were infected and ODYSSEUS “arrested” enough people to just about fill up the prison, Presper’s men would stage an attack on the prison which would allow everyone to escape. This event would start a countdown of sorts for missile launch on the ballistic satellite. ODYSSEUS would assess the viral spread, try to gather up the escaped prisoners, and, once 90% of the prisoners had been retrieved, launch nuclear missiles to “clean & prevent” any further infection. By the time this happened, Presper had planned to be on, and in full control of, the ballistic satellite and reprogramming targeting solutions to clean the areas he wanted. Humans of his choosing would wait out the second nuclear holocaust in the Boulder Dome, until the day came where he declared the Earth safe for pure blood humans once more.
The Prisoner would then be able to repair and then use a spaceship to infiltrate the ballistic satellite. From there, the Prisoner would decide which course to take. Would they buy into Presper's vision of a new, better world, or would they put an end to Presper's plan by neutralizing the scientist and stopping his missiles? Alternatively, the Prisoner could use those missiles to settle some grudges of their own.
The video then goes on to talk about how there seems to be a general misconception about the storyline in Van Buren. New Vegas did take some clear inspiration from Van Buren, but for the most part the events in New Vegas would have occurred after the events of Van Buren. In many ways, New Vegas represents the storyline that would have been featured in the version of Fallout 4 that Interplay was planning.
TL;DR: The player is sick and in quarantine. The player escapes and infects many. The player wishes to have a better understanding of the cure and through doing so finds out a mad scientist is responsible for getting people sick in order to for most people to die. The player confronts the scientist in space and either a) teams up with the scientist and most people die or b) stops the scientist and (at the very least) some people die.