An ancient organization hidden beneath the Metropolitan Public Library dedicates itself to protecting an unknowing world from the secret, magical reality hidden all around. The group solves impossible mysteries, fights supernatural threats and recovers powerful artifacts, including the Ark of the Covenant, the Spear of Destiny and Excalibur.
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.
Jenkins discovers there is something wrong with the library; the librarians are drawn together to solve the mystery of a massive storm that is parked over Manhattan.
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. AKA Coyote
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.
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.
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.
When the Egyptian God of Chaos inhabits a human body, he attempts to release Pure Evil into the world, thus beginning the final battle of Good vs. Evil. In order to stop him, the Librarians must decipher a series of clues within a science museum, including a mysterious warning spoken by exhibit mannequins that have come to life.
Flynn leads his fellow Librarians on a mission to rescue kidnapped Charlene, unwittingly ensnaring them in a subterranean trap filled with ancient Egyptian werewolves, led by nemesis Apep, who are determined to kill the Librarians once and for all.
After seeing a vision of her own death at the hands of a supernatural assassin, Baird tries to cheat fate and stop the deadly prophecy from coming true.
The librarians investigate a mysterious traveling carnival where they discover the sinister secret of a magician who has been corrupted by the use of real magic.
In order to stop the spread of Pure Evil, the team must find the Eye of Ra and unravel the mystery of The Bermuda Triangle. Flynn must also pass a series of tests that will help him find the eye and reveal a great deal about himself.
The obnoxious Cindy Kroger has suddenly become super-popular thanks to a magical love potion. The Librarians must stop her before she launches a love missile that would force the whole world to become her fan base.
A rash of people spontaneously combusting leads the Librarians to a holistic spa run by vampires, who have discovered the secret to walking in the sun.
When the Monkey King's sacred homeland of Shangri-La is taken over by a ruthless collector of magical artifacts, the balance of the Universe is put in jeopardy, forcing all the Librarians to come together to help save the imperiled land… at what could be a terrible cost.
The Librarians' two-front battle comes to a head when the Library is simultaneously infiltrated by DOSA and Apep. Flynn, Baird, Stone, Cassandra, Ezekiel and Jenkins must all put aside their differences in an attempt to save the Library, the world and themselves.
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 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.
A missing-person investigation uncovers what appears to be an alien invasion in a small rural town.
When Dulaque changes the course of Fate, Baird starts moving through alternate timelines, each showing the changing destinies of the Librarians - and her own inevitable doom.