In this episode, David Robert Jones employs former Cortexiphan subjects to create simultaneous earthquakes across the globe, leading Dr. Walter Bishop to hypothesize that the end of both the prime and alternate universes is imminent. The two worlds must decide whether to close the bridge that was repairing the alternate universe or they may all face destruction.
This episode's glyphs spell:
These glyphs foreshadow the reveal of William Bell being alive in the next episode.
The Observer can be seen in Sydney near Sally Clarke before she triggers the earthquake.
A flyer outside the nightclub in 'Letters of Transit' says "Experience the Epicenter Club", foreshadowing the earthquakes caused by Cortexiphan subjects in 'Worlds Apart'.
A sign for "Liberty Wind Chimes" in 'Worlds Apart' contains the Liberty Bell in its logo, hinting at the return of William Bell in 'Brave New World' (Part 1)'.
Lincoln recognized Nick Lane when they saw each other in "Over There (Part 1)".
They later have a similar exchange once their relationship develops.
In "Brave New World (Part 1)" Walter learned that William Bell was really behind everything. (Image 1)