A rail tanker in 'Neither Here Nor There' has "Brain Freeze" spray painted on it, foreshadowing the memory extraction process used by the killer in 'One Night in October'.
Professor McClennan's professional library in 'One Night In October' contains the book Killer Mindscapes by S. Pores, foreshadowing the fungi that can form mental connections with people from 'Alone in the World'.
FRINGE DIVISION CASE FILE #402-93011
FRINGE EVENT: Forced extraction of human memories
CLASSIFIED CASE CONNECTION(S): Serial killer, Over There universe
AGENTS ASSIGNED: Dunham, Lee, Bergmann (OH)
SUPERVISING AGENT: Broyles, Colonel Broyles
FILE ARCHIVED BY: Marvin Sommershof
WITNESSES/CONTACTS: John Louis McClennan (suspect; deceased; OT), Megan Miller (OT)
LOCATION: Norristown, PA (OT); Weir Farm, PA (OT)
VICTIM(S): Jeremy Roman (deceased; OT), Noreen Miller (OT), John Louis McClennan (OT)
CASE REPORT SUMMARY:*Highly classified—security access 7 and above*
ASTRID to Olivia: "Do you ever think that maybe your type just doesn't exist?"
BROYLES: "At the risk of sounding sentimental, I've always thought there are people who leave an indelible mark on your soul. An imprint that can never be erased."