Every episode of Fringe contains a hidden clue that foreshadows something in the next episode. In Fringe #402 "One Night In October", the author of the book "Killer Mindscapes" is S. Pores - as in SPORES.
In the Fringe episode "Alone In The World", the fungus that attacked the two boys released spores when it was brought back to the lab:
WALTER: Spores. I--I had assumed that the mold was just a symptom of the rapid decomposition.[Transcript for "Alone In The World" from Fringepedia.net]
ASTRID: Walter, I am not following.
WALTER: The cause, Astrid... I'm starting to believe that it was an aggressive form of fungi that killed the boys.