When Katie Fera, the Pip-Boy assistant technician of Vault 108, and her twin brother, Avian Fera, a guard from Vault 108, decide to take a look at the Overseer's terminal, looking for trouble. What they find instead is much, much worse. Avian quickly escapes from the Vault that night and Katie is thrown out of the Vault to find him and kill him. Of course, her (not actually but close enough) sister, Maloney Pines, the Vault Loyalty Checker, comes with her. Will Katie kill her brother, or join him in his battle to rule the Wasteland and take revenge on the Overseer for what he's done?