The Librarians investigate when a mascot goes missing from a university campus notorious for its connection with the occult. They soon learn that disappearances aren't just uncommon at this school, they're pretty much the norm.
They split up to investigate, and Cassandra and Ezekiel run into Lucy Lyon, a student who is investigating the existence of magic. She's not too far off, much to their discomfort, but she's able to get the two of them into a frat house to investigate.
Jake and Eve, meanwhile, go to speak with an architecture professor, who gets abruptly abducted by a tentacle monster that reaches through a rip in the fabric of reality.
Jake enlists the professor's students to help investigate, and they realize that the entire campus is basically sitting smack on a giant summoning portal. Cassandra realizes that the initial portal was opened by Lucy's particle accelerator project, and the rip is now self-perpetuating.
Jenkins identitfies the monster as a Lovecraftian creature that feeds off pride, but they are too late to prevent it from stealing away Lucy.
Cassandra declares that they are going to cross to its dimension and rescue Lucy, despite the danger to the school. She successfully locates Lucy and is rescued herself by a mysterious woman who offers her the chance to join the Lake, a group that understands both science and magic.
When they all return to the Library, Jenkins warns Cassandra about the Lake's ambitions.