In the third season of The Librarians, our heroes will face their greatest challenge yet as they go up against the ancient Egyptian God of Chaos to stop him from releasing pure evil into the world. The stakes are especially high, and one Librarian may have to make the ultimate sacrifice to save the world. The team also confronts a new antagonist, D.O.S.A. – The Department of Statistical Anomalies – whose mission is to apprehend the Librarians and take control of the Library and all the magical artifacts hidden inside. Discovering that there are brand new artifacts in the world, the Librarians find themselves torn between the power of magic and the harm those who use it can cause.