第 4 季 共 12 集
播出时间：2017年12月14日
第 1 集 And the Dark Secret
播出时间：2017年12月14日
When a secret sect of the Vatican Church unearths an ancient map detailing the locations of the four cornerstones of the Library of Alexandria (the original Library), it’s up to Flynn and the Librarians – with the help of an unexpected ally – to stop them before the stones can be used to destroy the Library.
第 2 集 And the Steal of Fortune
播出时间：2017年12月14日
When people begin getting hurt in the unluckiest of ways, the Librarians are led to a casino where the owner appears to possess an artifact capable of stealing people's luck. Despite falling under the bad luck curse themselves, the Librarians must turn the tables before the plague of bad fortune spreads to the wider world.
第 3 集 And the Christmas Thief
播出时间：2017年12月21日
When Santa takes Flynn, Baird and Jenkins on his first vacation in centuries, he leaves his beloved sleigh in the care of the Librarians. But when Ezekiel's career criminal mother steals the magic door, they must use the sleigh to save her, as well as Christmas itself, from Santa's Grinch of a brother, the Patron Saint of Thieves.
第 4 集 And the Silver Screen
播出时间：2017年12月21日
When Flynn and Baird are sucked into Baird's favorite classic Film Noir movie, the Librarians are drawn into the world of movie magic - literally - where they'll need to perfect their lassoing skills, sharpshooting, and snappy dialogue if they're going to make it out alive.
第 5 集 And the Bleeding Crown
播出时间：2017年12月28日
A Librarian from the past teams up with the Librarians of the present to take down an ancient and powerful enemy let loose in the modern day. When superfan Flynn is met with the prospect of teaming with his Librarian hero Darrington Dare, he could not be more excited, until Darrington leaves the Librarians with this dire warning: There can be only one Librarian - ignore at your own peril.
第 6 集 And the Graves of Time
播出时间：2017年12月28日
When Baird goes after Nicole Noone in an attempt to repair her rift with the Library, she ends up joining Nicole in a mission to retrieve a dangerous artifact before it falls into the hands of Russian grave robbers. But can she convince Nicole to forgive the Library and return home with her? Or, will Nicole open Baird's eyes to the dangers of a Guardian dedicating herself, heart and soul, to the Library?
第 7 集 And the Disenchanted Forest
播出时间：2018年1月4日
When dissension threatens the group, Baird takes the Librarians to a charismatic self-help guru’s team building camp on the edge of a forest where people have been mysteriously disappearing. Is there a monster in the woods? Or is something more sinister going on? And can the Librarians get their team mojo back in time to defeat it?
第 8 集 And the Hidden Sanctuary
播出时间：2018年1月11日
After Cassandra freezes up during a mission, she decides it's past time to go on a vacation. Searching for her ideal town, she lands on Havenport, the "Safest Town in America." At first blush, it seems just what she needed.
第 9 集 And a Town Called Feud
播出时间：2018年1月18日
When a Civil War re-enactment in a town called Feud is plagued by ghosts, the Librarians have to uncover the truth of what really happened there over 100 years ago.
第 10 集 And Some Dude Named Jeff
播出时间：2018年1月25日
When Jenkins body-switches with a 28-year-old slacker named Jeff, he must find his way back into the Library to correct the mistake. But he will need a team to do it, and enlists the help of Jeff’s hapless Dungeons & Dragons friends. Can they make it in time, before Jeff destroys the Library?
第 11 集 And the Trial of the One
播出时间：2018年2月1日
It's time to choose the singular Librarian to tether with Baird, but no one can decide so the Library takes it upon itself to help. Reducing the Librarians to their most primal selves and abandoning them in a landscape of their own nightmares, it's The Trial of the One - but can they regain their humanity in time to stop the bloodshed and prevent the death of two Librarians AND Jenkins?
第 12 集 And the Echoes of Memory
播出时间：2018年2月8日
After the world is morphed into a horrible and unrecognizable place – one where the Library never existed – it's up to Baird to bring the Librarians together before this bleak, knowledge-less world becomes the new reality.
