It's the Librarians' day off, but all of them still find themselves at the library.
The book alters them to something important, and they find that there is trouble at the Chicagoland STEM fair. Cassandra is thrilled at the idea of going to a STEM fair and explains to everyone why STEM fairs are exciting and important.
The Librarians are transported to an impressive fair at a high-school, where Jacob puts on the charm and telsl the woman in charge they are the Librarians. She understands this to mean they are judges from the local library, and they all find themselves viewing various projects.
When what looks to be a simple volcano causes a large explosion, the Librarians realize there something suspicious happening. They start questioning the students, and Jenkins arrives to help.
Other odd things continue happening at the fair, including insects flying out of a students' mouth.
Jacob talks to a guy who was hoping to win over one of the girls at the STEM fair, Amy. He gives him advice.
Jacob realizes that almost everyone hates Amy. Amy's mother is a little too involved. Ezekiel grabs her phone to see if she is involved.
The Librarians need to find three members of the coven.
Someone turned a magic spell into an app. However, they realize Amy isn't the one using magic. Amy tells Cassandra that her mother downloaded the app, but she didn't use it.
Amy wanted to be normal. She wanted to be something other than being "smart." Cassandra can identify.
Then she tells Ezekiel about how her parents threw out her trophies when she dropped out of school.
Jenkins runs into the woman running the fair, and she is at the Library. The woman in charge is Morgan le Fay. She's incredibly powerful. Eve tries to shoot her, but Morgan stops the bullets.
To stop the magic, Cassandra suggests they create a "Faraday Cage."
Eve uses Morgan's magic against her. Eve has to choose between killing Morgan and saving the kids. She chooses to save the kids.
They create a giant pentagram, and Eve finds herself alone with Morgan. Morgan says she now has enough power to hide.
Morgan alludes to more secrets with Jenkins. Then Eve finds herself back at the fair as it should be.
Ezekiel steals the trophy for Cassandra.
Jenkins is angry with Eve for letting Morgan go.