Olivia uncovers a dangerous force that may be connected to past experiments with Cortexiphan. The investigation forces Walter to leave the lab for the first time in years and travel to Massive Dynamic to examine old case files. Walter struggles with his emotional state as he confronts the demons of his past.
This episode's glyphs spell:
This foreshadows the fact that Peter's relationship with the other characters has essentially been reset back to square one in the next episode.
The Observer can be seen watching on as Peter is pulled out of Reiden Lake.
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'.
The labels "GOOD", "EVIL", "TRANSFORM", and "EJECT" on the wall in 'Subject 9' hint at the Shapeshifter plot in 'Novation'.
This is a foreshadowing of the timeline in which Nina raised Olivia and Rachel as her own children.