I did find a link to youtube that was suppose to be a walkthrough but it has been removed. I would appreciate it if someone could point me to where I need to go. I'm new to Fallout 3 and haven't discovered a lot of the map yet, but I have tried to go north from the hideout like the note said to uncover any clues, but without any luck. I can't figure out where I need to go to do this quest to get the key. The vault includes all the amenities including a stocked Armory, Display areas, Item Sorters, special Weapons, and is Companion Ready. Underground Hideout NLF - Adds a Player Vault on the South East end of the Wasteland near Rivet City. Fallout 3 Reanimated - A re-animation of human characters for fallout 3. The vault includes all the ammonites including a stocked Armory, Display areas, Item Sorters, special Weapons, and is Companion Friendly. Fallout 3 - Underground Hideout This Mod adds a Player Vault on the South East end of the Wasteland near Rivet City.