Take it Back!

 is a Fallout 3 quest. It is also an Xbox 360 and PC achievement. Take It Back! is the final main quest, with the game ending immediately after its completion. In this quest, the player and the Lyon's Pride assault the Jefferson Memorial in hopes of activating Project Purity. A colossal, crude, yet brutally effective robot paves the way, annihilating numerous Vertibirds and Enclave soldiers, although it also destroys the force fields erected by the Enclave. However, the ill equipped Lyon's Brigade is massacred by a barrage of missiles and small arms fire, leaving the path strewn with the gruesome remnants of Enclave and Brotherhood of Steel soldiers alike. When the player and the remaining Lyon's Brigade members finally reach the Project Purity control room. The player is then presented with a difficult decision, to either activate Project Purity, and thus fill the Wastelands with life, allow Sentinal Lyons to activate Project purity, or inject a virus that will kill any irradiated beings who come into contact with water. However, the control room is victim to heavy amounts of radiation, enough to kill a human in mere seconds. If the player opts to resign themselves to this legendary fate, to purge the Wastelands of adverse water, they succumb to the radiation, for the betterment of humanity. Sentinel Lyons also assures the player that they will never be forgotten, and forever revered for their life-giving deed.