我們知道的真實，幾乎已消失，被邪惡的Dulaque改寫，他曾是過去英勇的蘭斯洛特爵士，然而他的計畫遭到圖書館員的阻撓，原先的圖書館將再次恢復，新的一季跟著原班卡司，也有五個在圖書館工作的新角色登場。魔法還在持續，他們將解決看似不可能的神祕事物與保衛具有魔力的工藝品，平衡了魔法世界的秩序。
‘’不怕壞人，只怕英雄”- Jenkins
Reality as we know it was almost lost and set to be re-written by the evil Dulaque; formerly the valiant Sir Lancelot. But his plans were stopped by The Librarians and the original library was restored. This new season follows the original cast and introduces five new characters who work for The Library. The magic is set to continue, the solving of seemingly impossible mysteries and the protection of powerful artifacts to bring balance to the world of magic.
“Do not fear the villain. Fear the Hero.” -Jenkis
好萊塢型男Noah Wyle在飾演本劇的Flynn。
《X戰警》的魔形女-麗貝卡羅梅恩(Rebecca Romijn)飾演Eve。
Christian飾演本劇的Jake。
John Kim飾演本劇的科技智多星Ezekiel。
清麗女星Lindy飾演Cassandra。