
However, the sacrifice of the copied ED-E doesn't affect the ED-E that exists in the Mojave Wasteland, and it manages to transfer its memory to its other self just before exploding.
The player get to make one at the end of Lonesome Road either allow a barrage of nuclear ICBM'S to be launched, destroying either/both the only usable path into the Mojave from the West, or/and obliterating most of Arizona, or asking the copied ED-E to sacrifice himself to stop the missiles. Go through the top floor of the building and descend to the entrance of Ulysses' Temple. Make a slight drop and turn west to pass a lifted fence walkway between two rocks. Then backtrack to the flattened building and pass it.
Follow the path past the rock face to the southwest and get rid of the wedged in nuke that's dangling closely above a building. Go slightly up the building, but make an immediate turn around the rocks at the building's base, going south towards the wastewater treatment plant. Go around it and detonate the nuke that comes in sight, creating a path leading up and over the previous building. Look straight upward to see another nuke buried in the rocks above the temple's entrance.
Immediately beyond it, look up to the right to discover a warhead in a marked men camp.
Once the warhead is gone, a path below a building becomes a passageway towards Ulysses' Temple. Outside, go straight northwest, to find a warhead blocking the path to the east of the flattened building. To leave it, detonate the warhead that's fallen down with the rubble blocking it. The explosion has caved in the entrance once entered. Go past it and enter a small cave, where a warhead will be in plain sight sticking out the rocks. Go around the flattened building towards a sewage pipe.
After arriving on the Boxwood Hotel roof, having lost ED-E, descend the stairs and head south.