Losing their anonymity in Walter's Lab, the science team is forced to make a bold grab for written technical plans left in a childhood hiding place that Walter remembers. Meanwhile, Windmark and Broyles intervene and the team is driven-off with a devastating personal loss.
This episode's glyphs spell:
The loss of Etta wounded Peter to his very core, setting him up to face the same challenge Walter once faced: how far would you go to make things right after the loss of a child?
Observers are featured in this episode.
A sign picturing a dove on an old building in 'The Recordist' foreshadows the first mention of "The Dove" in 'The Bullet that Saved the World.'
Graffiti on an overpass in 'The Bullet that Saved the World' reads "Manifest Destiny", foreshadowing the Observer's shipping manifest the Fringe team decodes in 'An Origin Story.'
Walter retrieved his plans for destroying the Observers from a hiding place in a wall in the subway platform beneath Newark-Penn Station in "The Bullet that Saved the World".
Etta died in "The Bullet that Saved the World".