Peter's reappearance was the first step in resetting characters to the way they had been in previous seasons.
The Observer
The Observer can be seen watching on as Peter is pulled out of Reiden Lake.
Timestamp: 38:50
Episode Clues
Previous Episode Clue
A book titled Astral Projection and Other Psychic Phenomena in 'Alone in the World' can be seen in Walter's Lab, foreshadowing the astral projection ability Cameron James demonstrated as a child in 'Subject 9'.
Timestamp: 39:30
Next Episode Clue
The labels "GOOD", "EVIL", "TRANSFORM", and "EJECT" on the wall in 'Subject 9' hint at the Shapeshifter plot in 'Novation'.
Timestamp: 27:34
Items of Interest
Walter called Astrid 'Claire'.
The green and yellow posters in the diner represent how this new timeline with the yellow/amber title sequence is starting to merge with the original timeline with the blue title sequence now that Peter has returned (blue + yellow = green). (Image 1)
Peter reappeared in Reiden Lake, the place where he drowned in this rewritten timeline. (Image 2)
Image 1: Green and yellow posters Timestamp: 23:44Image 2: Peter in Reiden Lake Timestamp: 38:39
The Timeline Without Peter
Walter hated Nina because he blamed her for breaking the vial with the cure for Peter's disease which ultimately led to the kidnapping and Peter's death.
Olivia ran away from the Cortexiphan trials.
Bell was dead, as far as Walter knew.
Elizabeth committed suicide after both Peters died.
Olivia hadn't heard about/from any of the other Cortexiphan subjects until Cameron James.
Olivia had never heard of Reiden Lake.
Cameron James Timestamp: 36:48
Walter's Food
Walter ate peanuts, ate a frosted strawberry Pop Tart, packed sandwiches for a trip, and had root beer floats with Olivia (and taught her the best way to drink them).
Peanuts Timestamp: 03:46Frosted strawberry Pop Tart Timestamp: 06:15Root beer floats Timestamp: 21:06
Names for Astrid
Walter called Astrid 'Claire'.
Connection Chart
A visualization of all the ways this episode connects to other episodes. Scroll down to see the actual connections.
Episode Connections
S1E01 - Pilot
NINA SHARP to Olivia in 'Pilot': "I would say this to my own daughter..."
This is a foreshadowing of the timeline in which Nina raised Olivia and Rachel as her own children. NINA to Olivia in 'Subject 9': "So you told me about the Fringe Event, but I think you left something out. It's happening to you, isn't it? Now, come on. I haven't seen this much fear in your face since Bobby Hastings asked you to the prom. So what can I do to help you, dear?"
S3E10 - The Firefly
In 'The Firefly' Walter learned that his favorite band, Violet Sedan Chair, broke up after just one album because of an unlikely chain reaction of events started by Peter in 1985. In 'Subject 9', which takes place in the timeline where Peter was never raised in the Blueverse, Walter has a poster for a Violet Sedan Chair project that never happened in the original timeline.
Violet Sedan Chair poster S4E04 - Subject 9 Timestamp: 14:08