The Lone Wanderer lived in Vault 101 without incident for nineteen years, but in 2277, 200 years after the Great War, James disappeared without any explanation. The young Lone Wanderer, with the help of Amata Almodovar, left the safety of the Vault to look for James in the ruins of Washington, D.C. In order to find him, the Lone Wanderer traveled across the wasteland searching for clues. Along the way, (s)he may or may not have disarmed or detonated Megaton's atomic bomb and/or helped collect the data for Moira Brown's Wasteland Survival Guide, among many other activities or rumors thereof.
After James was found, Project Purity could be put back on track, but the reunion was cut short when the Enclave commander, Augustus Autumn, arrived demanding control of the project. James, unwilling to allow the project to fall into the hands of the Enclave, sacrificed himself by filling the control chamber with deadly amounts of radiation, hoping to kill Colonel Autumn and the other soldiers in the process. The colonel managed to survive, however.
After fleeing from the Jefferson Memorial, the Wanderer took refuge within the Citadel and enlisted the help of the Brotherhood of Steel to retrieve a G.E.C.K. from Vault 87 for the restoration of Project Purity. After retrieving this G.E.C.K. the Wanderer was captured by Colonel Autumn and taken to Raven Rock. There, John Henry Eden presented the Wanderer with a canister of modified FEV for insertion into Project Purity, which would poison any mutated creature drinking the purified water. The Wanderer refused and escaped, sabotaging Raven Rock in the process. After finally stopping Colonel Autumn, the Wanderer and Sentinel Lyons were faced with the dilemma of who would re-enter the radiation-flooded Memorial and activate the purifier. Once this decision was made, the Wasteland was finally given the greatest gift of all: a constant source of clean water.
Broken Steel The Lone Wanderer awakens two weeks later to face the consequences of their decisions so far and joins the Brotherhood as a knight, in their mission to distribute the newly-purified water and to hunt the Enclave remnants. This hunt would eventually put the Wanderer in control of an orbital strike. The Lone Wanderer either uses it to destroy the Citadel or the Enclave mobile base crawler. During or after the events of Fallout 3, the Lone Wanderer travels to various places such as The Pitt, Point Lookout, Mothership Zeta and participates in a simulation of the Anchorage Reclamation.
By 2297, the Lone Wanderer had disappeared from the Capital Wasteland, and their fate was unknown. Most citizens of the wasteland had a story about the Wanderer, and many of his or her actions had gone down as local legend. History had even forgotten whether they were a man or a woman. Much of the documentation of their actions had however became flawed, and were riddled with conflicting reports. On the 10th of September, Moira Brown began work on a biography of the Lone Wanderer.