Fallout 3's protagonist returns as a faction leader, quest giver, and (in the final chapter of the mod) player companion. The player will be able to customize the Lone Wanderer - including sex, appearance, and many backstory elements - to align with their FO3 playthrough.

The past decade has not been kind to the Lone Wanderer. After defeating the Enclave, providing clean water for all, and generally changing the face of the Capital Wasteland, she made the mistake of trying to unite the region's settlements under a common banner. And it almost worked - wastelanders were all too happy to rally behind their local hero. Hard-liners within the Brotherhood of Steel, however, saw her as a threat to the Brotherhood's mission and to its very identity. Conspirators arranged the murder of newly-elected Elder Sarah Lyons and framed it as a coup attempt by the Lone Wanderer. After a short civil war, the Wanderer and her allies were forced to retreat from the Capital Wasteland to their last stronghold, the Pitt. By the time of Fallout 4, she has forged a small but fiercely loyal nation: the Wanderer's Union.

In terms of characterization, the Lone Wanderer still bears the scars of watching her dreams turn to ash, but uses them to fuel her determination to get it right this time. She practices constructive paranoia, and will outright admit to the player that she's set up three different contingency plans to kill them if they betray her. She has learned from her enemies' success and now eagerly plays the part of the chessmaster, manipulating powerful people and factions (including the player) into doing her dirty work. Still, she's never lost her genuine hope for the future of mankind, or her ability to care for those close to her. Depending on the player's actions, her feelings for FO4's protagonist will develop into admiration for a heroic peer - or at least grudging respect for another one-person army!