Stan Lee (who created The Incredible Hulk) appears as a scientist presenting a gamma ray experiment for the manned mission to the moon Titan. When Fargo dismisses his work, Lee tells him "Don't make me angry. You wouldn't like me when I'm angry", and the theme music for The Incredible Hulk (1978) is playing softly throughout the scene. Also behind him is an Xray of a skull similar to the one used in the pilot episode of the Incredible Hulk TV series.
In 'Glimpse', Jo uses the threat assessment device while looking at Zane. A list of known aliases appears briefly. One of these, I.P. Freely, was mentioned in 'Liftoff' as the name Zane used to enter a lab in Global Dynamics.
In the season four episode "Glimpse," Zane gives Jo a threat assessment program which is directly installed on her eyes. Moments later when looking at Zane, Jo is provide a list of known aliases for Zane which include the names David Lightman and Stephen Falken. Lightman and Falken are the main protagonists of the 1983 classic science fiction movie WarGames, played by Matthew Broderick and the late John Wood. In the movie, Falken is an early programmer and AI researcher who himself is given an alias of Robert Hume.
Holly wears a Claddagh ring. The Claddagh, along with the Shamrock and the Harp are National Symbols of Ireland.
Felicia Day (Holly Marten) and Will Wheaton (Isaac Parrish) appeared together and were a short-lived couple in Season 3 of the online series, The Guild.