Peter awakens from a dream of his Olivia and Walter making him more determined than ever to get home.
When Walter tells him he will not be of assistance, Peter goes to Olivia and Lincoln for help to transfer over.
Walternate is not responsible for the new shapeshifter prototypes.
Someone is removing Fringe division from cases on the other side.
Lincoln has his first visit to the alternate universe and seeing the World Trade Center still standing literally stops him in his tracks.
Peter and Lincoln are found on the other side. Walternate ensures they are separated from Altlivia and Alt Lincoln and arranges to have them killed.
Altlivia begins to question whether Olivia may be right in her paranoia about Walternate.
Peter goes to see his mother, and she recognizes him. She's very strong, with a fierce belief in Walternate.
Walternate trusts Peter to deliver a message to the other universe to keep them from fighting, to tell them that they are not enemies but both being infiltrated by the same force.
Alt Broyles is not the gentle soul we know in our old alt universe. He's helping David Robert Jones, who is behind the new shapeshifters.
Olivia encounters her first Observer, who comes bearing unpleasant news.