Our story begins in a vault within the lands of what was once called Florida. Somewhat similar to the other vaults of the fallout universe but, it was secretly made by REPCONN instead of Vault Tec to house astronauts and their families. The purpose was that someday the people there may find a home in a star system called Alpha Centauri. In this system, there is a very small moon, slightly smaller than our own, that is hospitable to humans. The dwellers of the vault call it planet Oasis.

The player is born in the vault around the year 2225. His parents are the lead engineers of the vaults space program although personally they believe with some work and time that earth can be saved and have secretly been working on a water purification project with a small, separatist humanitarian sect of the enclave via radio and computer, known only as Gannon’s, but upon the birth of their son they keep their opinions and work to themselves so has not to be exiled in the harsh wasteland jungles of above. After the player is born the timeline fast forwards to the players 13th birthday where all vault dwellers are to begin there astronaut training. Unfortunately due to the unforeseen global warming the launch of the ship is nearly impossible. Clinging to the only hope that they have left, the dwellers keep up with the astronaut training in case someday that it is possible. As the player begins his training he learn simple things like how to survive on a uninhabited planet (teaching wasteland survival recipes) and how to shoot a laser weapon, using explosives, etc. the timeline then fast forwards again to the players 21th birthday when he is to take his astronaut certification test. This is where the tag skills and attributes using S.P.E.C.I.A.L are set. Upon passing, his parents congratulate him and decide to tell him about the secret water purification project they’ve been working on. After telling the player about the project his parents are called to the main reactor for unknown reasons. The player then walks the vault for a moment but then the warning of a radiation leak goes over the automated speaker system. The player rushes towards the main reactor to try and save his parents but is too late. The player sees his parents dying through the glass window and through a speaker they tell him that he should abandon plans for oasis and take the water project to the surface where his parents have a contact that will be able to help. Because the reactor shut down after radiation leak, the pumps that keep water out of the vault have shutdown causing it to begin to fill with water. The player quickly rushes out of the reactor area to the living quarters to tell people to get out of the vault initiating the quest “let my people go”. The overseer comes over the loud speaker telling people to go to the launch pad and that they will be leaving for oasis now. Knowing this is suicide, the player rounds up as many people as he can and heads for the vault door. Once there the controls have been overridden by the overseer. The player chooses to go back to the office to open the vault door. Once there he finds the overseer committing suicide. The player quickly hacks the terminal to open the door. Once the door opens he ran back up to the living quarters but the main staircase buckles under the weight of the water and quickly collapses. The rushing wall of water carries him to the launch pad door. The player quickly opens the door and shuts it behind him finding some the vault dwellers inside it. They ask him to pilot the rocket. With no other options left he decides to do it and climbs into the cockpit. The main doors open and the player starts the launch sequence. As the doors open, another wall of water is waiting above it causing the rocket to sluggishly move upward then once reaching the surface explodes from the bottom up. The cockpit is the only piece left soaring through the air. The player quickly hits the eject button as the cockpit hurdles towards a giant land mass opposite an even larger ocean. As he ejects, the launch chairs parachute fails to open leading the player assumingly to his watery grave, but at the last moment the parachute goes off but still leaving the player mostly unconscious from the g force and he blacks out.

The player awakens on a sandy beach to the site of a mirelurk just above him. The player shields himself from certain death when suddenly the creature is quickly shot in the head by a nearby scout. After the encounter the player initiates dialogue with the scout. His name is jaguar Juarez of the Aztec confederation. He tells the player how his great grandfather founded it after discovering there ancient ruins across the sea of the ancestors where he comes from and learned how there great power once ruled most of the lands. The scout goes on to tell him how he was supposed to be the ruler of his people but was slightly exiled to this far away jungle as a scout, due to a feud with his brother panther. The player tells Jaguar about the disaster at the vault and how his people were trying to get to a faraway planet called Oasis. The player then asks Jaguar if he can help him find some of the vault dwellers that may still be alive near wherever the vault entrance is. The scout then has the ability to become a companion to the player on his quest to find his people revive the water project of his parents to help rid the earth of radiation and purify it once and for all.