04E12 - Welcome to Westfield

When several cars stop working at a road to Vermont, followed by a plane crash, Olivia, Peter and Walter are assigned to investigate. On the return, Walter asks to stop at a diner to eat pie and they are attacked by the attendant that is killed by Olivia. They find most of the population dead and a wounded survivor called Cliff that explain that most people went crazy a couple of days ago. They meet a group of survivors and Walter concludes that people from both universes are merging in their doubles and they are trapped in the town. Only those that do not have double in Westfield have survived. But the greatest problem is that the town will be completely destroyed and only the center of the merged town will be a safe place.