
A Librarian -- a custodian of a magical repository of the world's most powerful and dangerous supernatural artifacts -- from the past travels to the present and finds himself unable to return to his own time. When he returns to his castle, which is now a museum, he inadvertently releases magic across the continent. In order to set things right, he is given a new team of Librarians to help him clean up the mess he made.

The team goes to a college campus with a world-class observatory to discover who is using the Crystal of Dr. John Dee to steal people's memories, in order to own the future.

When the magic door reroutes Charlie, Lysa and Connor to a bizarre manor where a series of Agatha Christie-style murders take place, they must figure out whodunit, while Vikram tries to track them down with the help of a mysterious tarot card reader.

Connor is forced to reconnect with people from his pre-Library life, and must defeat an old adversary who has grown powerful in his absence.

After a bachelorette party with Lysa's childhood best friend, the team wakes up in rough shape and hungover, with no idea how they ended up where they are.