Someone is killing off potential Librarians and it's up to Flynn Carsen and his new Guardian, Colonel Eve Baird, to save the three that are left.

The Serpent Brotherhood is trying to return magic to our world. Flynn, Colonel Baird, and the potential Librarians must stop them before it's too late.

The Librarians' first solo mission hits a snag when Baird loses the others in a mysterious Labyrinth that magically exists below the skyscraper of a modern corporation.

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.

The Librarians travel to a town where fairy tales are coming to life - and attacking.

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

The Librarians encounter the House behind the legend of ALL haunted houses and set out to destroy it.

An investigation into a missing person uncovers what appears to be an alien invasion.

Baird begins moving through alternate timelines that reveal the destinies of the librarians.

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.

Prospero summons other fictionals in order to retrieve parts of his staff; the librarians find themselves pitted against Frankenstein's monster and Sherlock Holmes' nemesis Moriarty; Flynn and Baird have a disagreement.

Stone, Cassandra and Ezekiel have a proper team-up for the first time in months when they investigate a cave-in at an oilrig site, which has unleashed Hokolonote, a shape-shifting god who grows in strength any time a lie is told. Now the Librarians have to come clean to each other, airing their issues and solving the riddle of the ancient prison that held Hokolonote.

Students start disappearing at Wexler College, an institution started by a mad historian/architect who believed in alternate dimensions. When the Librarians arrive, they discover a young student from the physics department is investigating the bizarre occurrences on her own. Meanwhile, Cassandra gets an offer that's difficult to turn down.

While chasing one of the Library's missing artifacts, Flynn is kidnapped by a mysterious stranger with both amnesia and a collection of all the Library's missing artifacts. Soon all of them are in pursuit of the Staff of Zarathustra before it falls into the hands of 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 Clipping Book sends the team to a high-tech research facility, where the researchers have been turned into mindless monsters by some bizarre power source in the center's lab. When they disconnect the artifact, however, they find themselves stuck in a time loop.

The team has scattered, all living the ideal versions of their lives. Soon these “strangers” are drawn together to solve a supernatural mystery – the appearance of Ariel, the sprite bound to Prospero's service. Can the Librarians do what no other human has ever been able – turn their backs on their own ultimate happy endings?

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.