Modified FEV

The modified FEV is a variant of the Forced Evolutionary Virus and quest item in Fallout 3.

Effects
It is given to the Lone Wanderer by John Henry Eden in Raven Rock and can be inserted in the Jefferson Memorial Rotunda, contaminating the purifier's filter system and, subsequently, the Capital Wasteland's waters during the quest Take it Back. It is not possible to leave the room where President Eden is located unless the Wanderer has picked up and retrieved the modified FEV from Eden's console. If the Lone Wanderer contaminates the purifier with the modified FEV, medical facilities fill with patients dying from FEV infection.

Related quests

 * The American Dream
 * Project Impurity
 * Take it Back!