Highest rated episode for the entire series
Dr. Mills declares Faded Giant protocol during evacuation procedures. Faded Giant is real United States military terminology. It refers to an event involving a military nuclear reactor or other radiological accident not involving nuclear weapons.
Brent Spiner appears as the voice of Puck. Spiner also provided the voice of Puck in the animated series Gargoyles (1994).
The Librarians encounter a Glenn-Reider security system. This safe and security system company featured prominently in Exec Producer Dean Devlin's show Leverage (2008), and is named for Melissa Glenn and Jessica Grasl (then Reider), two of the shows writers.
The Librarians avoid using the word "zombies" to describe the "rage people" that are attacking them, possibly as a nod to Lindy Booth appearing in Dawn of the Dead (2004). It could additionally be a nod to the "Not Using the 'Z' Word" trope that has it that no one in a zombie story ever says "zombie".