In this episode, Olivia, still trapped in the other side and brainwashed, investigates the Rose brothers who are able to do the seemingly impossible: escape from an amber-like substance used to contain fringe events. Meanwhile, Walternate experiments with Olivia again and she re-enters the tank while visions of Peter continue to haunt her about returning to the "other side."
This episode's glyphs spell:
The Observer can be seen in a line of people outside as the Fringe team spots Olivia's car.
Astrid brings Walter a magazine in 'Do Shapeshifters Dream of Electric Sheep?' with the word "TWINS" on the cover, foreshadowing the plot twist in 'Amber 31422'.
The Franklin St. Station subway sign in 'Amber 31422' shows the numbers 6-9-5-5, foreshadowing the radio station frequency investigated in '6955 kHz'.
People think that those who are ambered are dead; a group protested ambering the opera house in "Olivia". The public doesn't know that amber victims are actually alive. (Image 1)