https://www.pcgamer.com/fallout-3-mod-washingtons-malevolence-is-a-dlc-sized-quest-for-pre-war-riches/

Washington's Malevolence is a "DLC-sized quest mod" for Fallout 3 that takes players on a hunt for the Rocky Cape Bank on Maddox Island in Chesapeake Bay, rumored to be filled with untold prewar riches. Mod maker Adam "garfield2004b" Sweet said players "will get to explore the island, visit several new locations, and meet different people from different backgrounds that will shape and mold the events that take place." 

"This project has been a self-built labor of love for the past 5 years of my life. Without the help of a great team of voice actors, this project may have never seen the light of day," Sweet wrote. "I'm proud to finally release this thing out into the open; I'm very excited to share the story of Maddox Island and its inhabitants with you, the player."