When the Serpent Brotherhood wants to kill Santa, the Librarians must rescue him and help him accomplish the true, secret purpose of Christmas.

When the dragons sleeping beneath the earth threaten to awaken and wreak havoc around the world, Flynn returns to help find their hidden treasure.

When a group of competitive high-school students start undercutting each other with witchcraft, the Librarians have to intercede before disaster destroys them all.

While Jenkins discovers there's something wrong with the Library since it returned from the Void, the Librarians all find themselves drawn back together after having been off on their own for months, to solve the mystery of a massive storm that has parked itself over Manhattan. They soon discover the culprit in both cases is none other than Shakespeare's Prospero.

An old friend of Baird's is running for Mayor of a small New Hampshire town and finds himself embroiled in a scandal in the form of a missing intern and a literal contract with the Devil. Baird soon finds herself in a battle not only for her own soul, but also for the souls of all the Librarians.

When people begin suffering the effects of accidents and sins in which they have not actually been involved, the team tracks the connection to the perpetually young Dorian Gray, whose magic now works on selfies.

The Librarians discover that Prospero's renewed magic is wreaking havoc with the technology of the world. He is recreating an idyllic forest utopia, whether we want one or not. In order to stop him, Flynn and Baird must travel back to 1611, while the rest of the team battles Prospero in the present. Little do they realize that they can only defeat Prospero in each time by finding a way to work together – separated by five centuries.