In 2010, he made contact with Peter and tried to convince him to use the machine (since according to an equally ancient drawing, the machine is attuned to Peter), but due to a budding relationship with Olivia Dunham (an FBI agent), he refused. Walternate then kidnapped Olivia and replaced her with her double, Fauxlivia. Peter, thinking that Fauxlivia was Olivia, started sleeping with her.
Fauxlivia was revealed to be an impostor, and returned to the other universe with a piece of the machine previously unknown and pregnant to Peter. She had a son, Henry. Walternate used Henry's blood to activate the machine, but it was turned off on this side. Because of this, Peter used the machine to destroy the other universe.
In the year 2026, Walternate attempted revenge on this universe, and managed to kill Olivia, but was stopped by Peter. 2026 Peter traveled back in time to 2011 to stop himself from destroying the other universe, but was erased from time. Walternate's 2011 fate is unknown.