I think the plot could begin with a small movie clip of a group of scavengers searching through the ruins of a old town or city, and in a cut scene it would show one of the scavengers find a opening in the ground so they lower a lantern on a rope down the hole and see that it isn't that far down, so thinking maybe they found some kind of underground bunker, they go down the rope with caution for fear of old automated defence systems, but what they find is the remains of a old underground car parking lot, as they look around one of them notices the lack of any vehicles anywhere around, so after a very short look around they find a elevator that goes down to a even lower level, so they pry the doors of the elevator open and try and get the elevator to work, but in doing so there tampering triggers a boobie trap and a toxic gas starts to flood the underground area, in a panic they start to run for the rope where they climbed down but before they can get to the rope most of them expire from the gas only a soul survivor makes it out of the undergground structure alive, cut scene deep under the parking garage is a secret lab where there are hundreds if not thousands of scientists and soldiers placed in some kind of cyrogenic stasis begin to awaken from there century's long sleep, in the background we see a emblem or logo we have never seen in the fallout series, a new menece has been awaken from a long sleep with with visions of there old glories still fresh in there minds they choose to mould this world in there image, cut scene a half dead scavengers makes his way to a town not to far from where to ruins were and is nursed back to health by a doctor there who hears the mans story before the scavenger leaves he say's to the doctor maybe god forgive me for the evil we have awaken, fade out mission begins.