Fallout 3 plot

Escaping Vault 101
You, The Lone Wanderer are a young inhabitant of Vault 101. The Vault has supposedly been sealed for the last 200 years, with nobody entering or leaving it. All was going well until your father, James disappeared from the vault without any explanation. The Vault Overseer believes that you knew about the escape and sends his people to subdue you, and forces you to leave the Vault and set off on a journey to locate your father and find the reason for his disappearance. You must then use the escape hatch under the overseer's desk to escape. This can be achieved by one of three ways. 1: confront the overseer, and after a speech check, obtain the hatch password from him. 2: kill the overseer and take the password from his body, or 3: hack the overseer's terminal in his office and activate the hatch from there.

The World
Rust, decay, and creeping vegetation infest monuments from before the Great War. Amidst the ruins of Downtown DC, The Capitol, The Jefferson Memorial and the battered remains of The Washington Monument still stand in the desolate area that is now known as The Capital Wasteland. The central hub of civilization in the ruins of the former capital is Rivet City, based in the remains of an aircraft carrier carried far inland and beached by a catastrophic tsunami whose waters have long since receded. Other settlements include the towns of Megaton, Arefu, Tenpenny Towers and Paradise Falls. Movement through the downtown area and settlements is possible through the Washington Metro tunnels and crossing the desolate nuclear wasteland.

The Brotherhood of Steel community is stationed in the Citadel built in the ruins of the pre-War Pentagon where they attempt to preserve as much pre-war technology as possible. Super mutants, who since emerging from their refuges, have waged an unceasing war against what remains of humanity, trying to invade their territory and capture them. The Enclave - the self-styled inheritors of the power of the United States government - under the leadership of their new President John Henry Eden, are the player's biggest foes in the game.

Finding Dad
As you search for your father, either through Three Dog, DJ of Galaxy News Radio, or by speaking directly to Madison Li in Rivet City, you learn that he went to the now abandoned Project Purity site located in The Jefferson Memorial. His, and the other scientist's aim was to complete Project Purity, and purify huge amounts of water for the entire wasteland. However, when you reach the Jefferson Memorial you find a holotape detailing his search for the brilliant Scientist Doctor Stanislaus Braun who worked for Vault-Tec before The Great War, and now resides in Vault 112. Doctor Braun invented the Garden of Eden Creation Kit (G.E.C.K.), a device meant to terraform the world after a nuclear holocaust.

Upon finding and entering Vault 112, you find that all the inhabitants have gone into virtual reality simulators, where they have remained since the bombs fell. After entering a stasis pod and loading the Tranquility Lane simulation, you find yourself in a picture perfect, pre-war town. You talk to Betty, who asks you to cruelly make another child cry. Upon doing so she begins to speak with a startlingly male voice and allows you to ask a single question which she will answer to the best of her ability. She then asks you to ruin Janet Rockwell and Roger Rockwell's marriage. Afterward, he asks you to kill Mrs. Henderson. Finally, Betty tells you that you must don the Pint-Sized Slasher mask and kill all the resident of Tranquility Lane. Alternatively, you can enter an abandoned house and by activating a set pattern of items in a melodic tune, you can make a fail-safe computer terminal appear. On the computer are the records of how Stanislaus Braun has been playing cruel games with the residents of the Vault, sadistically torturing them and then changing the simulation when it got "boring". Also, on the computer is a fail-safe program that initiates a simulation of a Chinese invasion (borrowed from the government at his request), which deactivate a "safety protocol" and physically kill the residents of the vault. However, Braun cannot deactivate his own safety and therefore cannot commit suicide, leaving him alone with no one else to torture if you choose this course of action. After completing one, or both these paths, Betty reveals that your father has been inside the simulation as the dog near him. You are then free to leave by a door that materializes next to him. After exiting the simulation, your father then emerges out of a stasis pod and tells you that he went to Braun because he wanted to confirm that the G.E.C.K could be used for Project Purity.

Finding The Garden of Eden
You must then go through Little Lamplight since direct entrance to Vault 87 is impossible, due to it having been hit directly by a nuclear warhead. You can convince Mayor MacCready to let you into Little Lamplight by using the Child at Heart perk or by freeing children captured by slavers in Paradise Falls.

Inside Vault 87 is Fawkes, a super-mutant that had access to the vault computers and their vast data banks, resulting in him being much more intelligent than the average super mutant. He was trapped in the room by the other super mutants who viewed him as a freak, and prefers to be called a meta-human. Upon questioning him, he offers to take you to, and retrieve the G.E.C.K. from the irradiated section of the vault if you free him from his holding cell. If you choose not to free him, there is a room with a Radiation Suit and Rad Away which can be used to reach the G.E.C.K. After having Fawkes retrieve the G.E.C.K or doing it yourself, you start to head back to Little Lamplight, but are ambushed and captured by Enclave soldiers before exiting the vault with the G.E.C.K.

Raven Rock
When you come to you find yourself in Raven Rock, an Enclave stronghold in the extreme northwest of the map, there Colonel Autumn questions you and asks you for the activation code to Project Purity. However, President John Henry Eden orders Autumn to come and talk to him. When the Colonel leaves, the President request an audience with you and deactivates your restraining field. The President orders the Enclave soldiers not to harm you, an order then promptly recalled by Colonel Autumn. You are then forced to fight your way through Raven Rock to Eden's office. You find that he is an advanced model of the ZAX Supercomputer and is actually an amalgam of all of America's former Presidents. He tells you that the only way to get humanity to function properly in the wasteland is through water. He also says that The Wasteland must be cleansed, which is why he does not allow you to leave until you have taken the vial of modified Forced Evolutionary Virus, which would kill all super mutants and Ghouls. You can then choose to destroy President Eden either through a speech check, Intelligence check, or find his self-destruct code and tell it to him. If you ask why Colonel Autumn cannot carry the F.E.V vial for him, Eden tells you that the Colonel does not agree with his plans. You may then leave Raven Rock. Afterwards, you find Fawkes outside, who came a little late to rescue you. You must then head back to Elder Lyons in the Citadel. If you decided you should infect the project with Modified FEV, the appearance of Fawkes is meant to make you see that it might not be such a good idea considering the fact that you have made such a loyal and powerful friend.

Taking It Back
You meet Elder Lyons down in the Citadel's lab. When you arrive, a heated discussion between Scribe Rothchild, Elder Lyons, and Sarah Lyons is taking place. Rothchild argues that Liberty Prime is not ready for action, while Sarah is arguing that there isn't any time for another plan. Eventually, it ends with Lyons giving up and allowing Sarah, and Lyons' Pride, to go to the Jefferson Memorial with Liberty Prime. Once you arrive at Project Purity, you confront Colonel Autumn one last time, and decide his fate. Then, you are faced with many difficult choices; enter the irradiated chamber of Project Purity and sacrifice yourself, make Sarah Lyons go in your place, or simply do nothing and let Project Purity explode around you. Along with this decision, you must also decide whether or not to put the modified F.E.V. vial into The Project Purity console or not.

Death from above
A fortnight after the events of Project Purity, the Lone Wanderer awakes inside the Citadel. The Brotherhood of Steel has engaged in an all out conflict with the Enclave. The Brotherhood of Steel has won every single confrontation with the Enclave mainly due to Liberty Prime. The Enclave was expected to be in complete disarray but this does not appear to be correct has they seem to have limited communication abilities.

The Brotherhood of Steel prepares to assault an Enclave communication building at the Satellite Relay Station led by Paladin Tristan along with the Lone Wanderer and Liberty Prime. As the Brotherhood of Steel breaches inside the station, an orbital strike fires upon them resulting in the destruction of Liberty Prime. The Lone Wanderer breaks through the Enclave along with three Paladins to discover an encrypted piece of information. The Lone Wanderer returns the information to Scribe Rothchild at the Citadel.