This episode follows the continuing disintegration of the prime universe as the Fringe team races to prevent the destruction of their world. FBI agent Olivia Dunham recruits Sam Weiss for help while Peter recovers from touching the doomsday machine.
Synopsis provided by the Fandom Wiki, Fringepedia, and Wikipedia.
This episode's glyphs spell:
The Observer can be seen in the crowd behind Peter Bishop when he looks for a pawn shop in New York City.
The lightning bolt bumper sticker on the rancher's truck in '6:02 AM EST' foreshadows the widespread lightning attacks in 'The Last Sam Weiss'.
The ID number "2026" on the squad car in 'The Last Sam Weiss' foreshadows Peter's experiences in the year 2026 in 'The Day We Died'.
When Peter was confused after getting zapped by The Machine in "The Last Sam Weiss" he went to a pawn shop and bought that same coin from a pawn shop. (Image 1)
Walter accepted Peter's destiny in "The Last Sam Weiss" and watched as Peter stepped into The Machine and activated it. (Image 1)
In "The Last Sam Weiss" a new parchment ("The Crowbar") was discovered that had Olivia's face on it. (Image 1)
In "The Day We Died" Peter revealed that the person responsible for the drawings and The Machine was Walter himself.
As Olivia continued to regain her memories in "A Better Human Being" she mentioned remembering the events of "The Last Sam Weiss".